The Role of Natural Honey as a Corrosion Inhibitor for Mild Steel in Hydrochloric Acid

The Role of Natural Honey as a Corrosion Inhibitor for Mild Steel in Hydrochloric Acid | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article The Role of Natural Honey as a Corrosion Inhibitor for Mild Steel in Hydrochloric Acid Ifeanyi John Obibuenyi, Uche Luvia Ezeamaku, Chigozie Onyechere, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5727302/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 3 You are reading this latest preprint version Abstract This research investigates the role of natural honey (NH) as a corrosion inhibitor for mild steel in hydrochloric acid. The materials used include mild steel, hydrochloric acid, a Fourier transform infrared spectrophotometer, and a scanning electron microscope. Experimental treatments were performed using gravimetric, polarization, and impedance methods. FTIR analysis revealed the functional groups present in the honey, and the polarization measurement reached a steady state at a potential range of approximately 250 mV after 30 minutes of immersion at a scan rate of 0.33 mV/s. The results also show that NH inhibited cathodic and anodic reaction processes when the displacement was greater than 85 mV and a mixed-type inhibitor when the displacement was less than 85 mV. The weight losses were recorded as the average value of the difference between the initial and final weights of the three determinant coupons at a given time. The efficiency was validated, and the 99.52% obtained was close to the predicted value of 99.13%. The negative value of binding energy implied an exothermic reaction. The molecular dynamic simulation with a high energy gap indicates that NH had a high reactivity of adsorption and could be a mixed-type inhibitor. For these reasons, NH was adjudged a mixed-type inhibitor and a good quality corrosion controller of metal surfaces. Physical sciences/Chemistry Physical sciences/Engineering Corrosion inhibition natural honey mild steel HCl efficiency Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 INTRODUCTION Corrosion is a global problem and an inevitable matter of great concern that requires constant attention to resolve. Indeed, corrosion leads to the depletion of our natural resources, especially in the metal industries [ 1 ]. Aggressive environments caused by corrosion in the presence of acids lead to the instability of metal structures and, hence, are most unfriendly to metals. The effect of this development often leads to serious problems such as surface dulling, high operational costs and maintenance, product contamination, downtime, loss of valuable products, and effects of safety reliability [ 2 ]. To solve the problem of corrosion, different techniques were employed, including the use of suitable corrosion inhibitors [ 3 – 6 ] and [ 7 – 11 ]. Metals were separated from corrosive agents while compounds containing inhibiting molecules were adsorbed at the surface of the metal where protective barrier was formed [ 12 – 14 ]. The obvious advantageous need and use of steel and their alloys lead to the quest for solutions to corrosion problems [ 15 ]. Some of these properties are good mechanical strength, high thermal conductivity, good electrical properties, etc. Previous studies have investigated the use of natural honey as a corrosion inhibitor in 0.5 M HCl media, with results showing that honey can effectively act as a corrosion inhibitor for metals like carbon steel. The use of honey also demonstrated a significant reduction in the corrosion rate when added to the acidic solution. The inhibition mechanism is generally attributed to the adsorption of honey components onto the metal surface, forming a protective layer against further corrosion. The highest rate of corrosion inhibition (93.5%) was attained at a concentration of 1800 ppm with an increase in the concentration of the extract [ 42 ]. Many other researchers have also reported their findings on the use of both natural and synthetic polymers to inhibit the corrosion of metals in aggressive environments [ 16 – 22 ]. Studies have also shown that natural honey can achieve high corrosion inhibition efficiencies in 0.5 M HCl, with the effectiveness often depending on the concentration of honey used. In this study, natural honey (NH), a dependable inhibitor, was used to control the corrosion of mild steel and its alloys in a 0.5 M hydrochloric acid environment. NH is friendly, low costing, and readily available, hence its choice in mitigating the corrosion menace. Key findings from this research showed that the inhibition efficiency was 99.13% at 10 g/L of NH and 50 o C. Detailed knowledge of characteristic inhibition-intake at the molecular level of the experiment using the inhibitor was provided with the aid of Quantum Simulation (Computational) Studies. One such theory is the density functional theory (DFT). This is useful means of evaluating the inhibitive efficiency of corrosion of different materials to predict functional centers of adsorption [ 23 – 25 ]. 2.1 MATERIAL Mild-steel specimen was purchased from local market. Other material include thread, desiccator, Fourier transform infrared spectrophotometer ( shimadzu , model: IR affinity – 1; s/n A2137470136 SI), PARC-23, electrolytic cell, power suite software, weighing balance, thermometer, thermostatic water bath, capacity beakers, glass rod, hooks, RSM design expert software, DFT electronic structure programs DMol 3 as contained in the Material Studio 7.0 software program, and XL-30FEG scanning electron microscope. Consumable materials include ethanol, distilled water, acetone, standard-grade HCl, NH, etc. NH was purchased from the dealers, while others were assessed from the institution’s laboratory. 2.2 METHODS The mild-steel specimen with the following compositions: 0.02% Si; 0.05% C; 0.18% Mn; 0.02% Cu and 99.73% Fe, was cut into 2 x 2 x 2 cm 3 dimensions and pressed mechanically. The coupons were degreased with absolute ethanol, washed, dried with acetone, and kept in desiccators. Undiluted 0.5 M hydrochloric acid was provided. Various concentrations (2, 4, 6, 8, 10) g/L of NH were prepared. The blank acid was prepared using distilled water inhibited with (50 mg/L and 1000 mg/L) NH respectively. This was similar to the method used in the processing of guinea corn by [ 25 ]. FTIR analysis of NH was performed at the Energy Center of the University of Nigeria, Nsukka. The spectroscope simultaneously collected the high-spectral-resolution data over a wide range and converted the raw data into an actual spectrum. The cylindrical electrolytic cell glass was used in the polarization measurement. Electrodes were connected to the electrochemical cell with the aid of a lugg-in capillary at room temperature (30 ± 1 o C). All measurements were performed, and the steady-state value OPC was obtained after 30 minutes of immersion. The study was done at a potential range of approximately 250 mV versus corrosion potential at a scan rate of 0.33 mV per second [ 26 – 27 ]. Extrapolation of data was carried out with the Power Suite software, and the system’s reproducibility was verified at an average of three attempts. Specimens were carefully prepared and immersed in 200 ml test solutions at 28 o C while performing the gravimetric measurement. They were then suspended in 250 ml test solutions with glass rods and hooks. The tests were conducted three times to ensure reproducibility in aerated solutions. After establishing weight loss, specimens were retrieved at 24-hour intervals for 120 hrs. The thermostatic water bath was maintained at 30 ° C, 40 ° C, 50 ° C, and 60 ° C for 6 hours. Weight losses were recorded as an average value of three determinant coupons. The corrosion rate of mild steel in 0.5 M HCl solution with NH was calculated with the following Eq. 1 [ 28 ]: Corrosion rate, \(\:x=\frac{876000\varDelta\:\text{W}}{{\rho\:}\text{A}\text{t}}\) (1) where, \(\:\rho\:\) , ΔW, A and t are respectively density, weight loss, area, and time. The percentage inhibition-efficiency was obtained with Eq. 2 [ 29 ]: \(\:\%\:I.E=\{1-(\frac{{R}_{ct}}{{R}_{ct\:inh}}\left)\right\}\:\) x 100 (2) where \(\:{R}_{ct}\) and \(\:{R}_{ct\:inh}\) are charge transfer resistances. Equation 3 was used in determining \(\:\theta\:\) (degree of surface coverage) [ 30 ]: $$\:\theta\:=\:\left[1-\left(\frac{C{R}_{pre}}{C{R}_{abs}}\right)\right]\:x\:100$$ 3 where \(\:{CR}_{pre}\) and \(\:{CR}_{abs}\) are corrosion rates. In designing the experiments, RSM was used, and design matrices were obtained. Similarly, ANOVA was carried out, and factors coded + 1 and − 1 were obtained. Quantum simulations were performed with density functional theory DFT. Similarly, molecular dynamics simulation examined the interaction between inhibitor and corroding surface and investigated inhibitors’ adsorption. Different low energy minima were sampled, and the global energy minimum was determined. Calculations were made at a fixed temperature of 25 ° C. The process was quenched every 250 steps. The total energy (rigid adsorption energy) plus deformation energy and substrate energy at the surface was taken as zero. Finally, the surface morphology of specimens after immersion in 0.5 M HCl in the absence and presence of NH was analyzed with the scanning electron microscope (SEM). 3.0 RESULTS AND DISCUSSION 3.1 RESULTS 3.11 FTIR result on the NH FT-IR result of natural honey is presented in Fig. 1 . About 20 peaks are identified. The spectrum with peaks shows absorbance on the vertical axis and frequency on the horizontal axis. Analysis of NH revealed the presence of C-H bend, =C-H bend, RCH-C’ R’’, C = O stretch, C = C-CH (R) OH, C-O stretch, Ro-O-H, N-H blend, R-C (O)-NH-R, C ≡ N stretch, carboxylic acids, C-H stretch of C = O aldehydes, O-H stretch carboxylic acid, N-H stretch amines-primary, hydrogen-bonded O-H stretch, carboxylic acids and N-H symmetric stretch amines. 3.12 Polarization Results The results of the Polarization experiment to distinguish the effect of NH-inhibitor on corrosion of mild steel are arranged in Table 1 . The NH was graded as an inhibitor which becomes cathodic or anodic when displacement was greater than 85 Mv and also a mixed inhibitor when displacement is below 85 mV. The electrochemical corrosion parameters, such as corrosion potential (E corr ), cathodic and anodic Tafel slopes (b a and b c ), corrosion current ( I corr ), and inhibition efficiency (%IE), obtained by extrapolation of the Tafel lines, are also shown in Table 1 . Table 1 Polarization of NH inhibitor on corrosion of mild-steel. Quantity \(\:{-\varvec{E}}_{\varvec{c}\varvec{o}\varvec{r}\varvec{r}}\) [E vs. SCE (V) Corrosion current \(\:{\varvec{I}}_{\varvec{c}\varvec{o}\varvec{r}\varvec{r}}\) (µΑcm -2 ) \(\:{\varvec{b}}_{\varvec{a}}\) (m V dec − 1 ) \(\:{-\varvec{b}}_{\varvec{c}}\) (m V dec − 1 ) IE (%) 0.5 M HCl -466.4 183 102.6 122.7 50 mg/L B -451.9 22.5 76.6 115.1 87.7 1000 mg/L B -461 10.4 73.8 104.2 94.3 Similarly, the Potentio-dynamic polarization curves plot for mild steel in 0.5 M HCl in the presence and absence of NH is shown in Fig. 2 . 3.13 Electrochemical impedance study of mild-steel corrosion in NH result Nyquist plot for mild steel in 0.5 M HCl in the absence and presence of NH at various concentrations were shown in Fig. 3 . The plot shows that, the diameter of the capacitive loop and consequently the value of the charge-transfer resistance, R ct increased with the concentration of inhibitor, which is an indication of the inhibitive action. In all cases, the semicircle corresponds to a capacitive loop. The semicircle radii depend on the inhibitor concentration. The diameter of the capacitive loop increased with increasing inhibitor concentration. The increase is more significant in fast green. The results show that R ct values increased with an increase in inhibitor concentration. As R ct is inversely proportioned to the corrosion current, it was used to determine the inhibitor efficiency. Electrochemical impedance parameters of mild steel in 0.5 M HCl in the absence and presence of honey at 30 o C. The high frequency intercept with the real axis is ascribed to the solution resistance \(\:{\varvec{R}}_{\varvec{s}}\) and the low frequency to the charge transfer resistance \(\:{\varvec{R}}_{\varvec{c}\varvec{t}}\) . It is obvious that the introduction of NH to the acidic environments increases the charge-transfer resistance, which inhibits the corrosion process. Table 2 shows the numerical values of the impedance parameters of NH at 30 o C. Table 2 Impedance parameters of NH at 30 o C. Quantity solution resistance \(\:{\varvec{R}}_{\varvec{s}}\) (Ω cm 2 ) charge transfer resistance \(\:{\varvec{R}}_{\varvec{c}\varvec{t}}\) (Ω cm 2 ) NH Capacitance , \(\:{\varvec{C}}_{\varvec{d}\varvec{l}}\) (F cm -2 ) Inhibition efficiency IE (%) 0.5 M HCl 1.659 102.7 0.89 6.908E-5 50 mg/L NH 2.964 724.6 0.89 4.730E-5 85.8 \(\:{10}^{3}\) mg/L NH 3.527 789.4 0.89 3.423E-5 86.9 3.14 Gravimetric Measurement Results The weight loss concerning time and concentration additive was established at varying temperatures as in Table 3 . They were recorded as the average value of the difference between the initial and final weights of the three determinant coupons at a given time. Table 3 Weight-loss of mild-steel in NH at varied temperatures. NH Quantity g/L 30 o C 40 o C 50 o C 60 o C Blank 0.160 0.350 - 2 0.017 0.020 0.026 0.032 4 0.013 0.015 0.020 0.024 6 0.010 0.012 0.015 0.017 8 0.008 0.009 0.011 0.013 10 0.006 0.007 0.008 0.010 The gravimetric (weight-loss) measurement results in Fig. 4 indicate that NH acted as an effective inhibitor. The corrosion rate of respective, mild steel in 0.5, 0.3 and 0.1 M HCl solutions with and without NH were calculated with Eq. 1. The corrosion rate result in Table 4 indicates the formation of stable corroded surface due to reduced potency of dilute acid with temperature. Table 4 Values of corrosion rates (%) IE and degree of surface coverage (θ) in NH. Quantity Corrosion rate Inhibition efficiency (%) Degree of surface coverage (θ) 30 o C 40 o C 50 o C 60 o C 30 o C 40 o C 50 o C 60 o C 30 o C 40 o C 50 o C 60 o C BLANK 26.94 58.93 155.23 155.23 ― ― ― ― ― ― ― ― 2 g/L 2.86 3.37 4.38 5.39 89.38 94.28 97.18 96.53 0.89 0.94 0.97 0.97 4 g/L 2.19 2.53 3.37 4.04 91.87 95.71 97.83 97.4 0.92 0.96 0.98 0.97 6 g/L 1.68 2.02 2.53 2.86 93.76 96.57 98.37 98.16 0.94 0.97 0.98 0.98 8 g/L 1.35 1.52 1.85 2.19 94.99 97.42 98.81 98.59 0.95 0.97 0.99 0.99 10g/L 1.01 1.18 1.35 1.68 96.25 98.00 99.13 98.92 0.96 0.98 0.99 0.99 Inhibition Efficiency result in Fig. 5 and Table 4 showed maximum efficiency 99.13% at 10 g/L of NH and 50 o C. The graphical analysis of inhibition efficiency of honey on the mild-steel in HCl environment are shown in Fig. 6 . Plots of Normal Residuals versus Studentized Residuals were used to test the significance of the model order. The residuals versus studentized residuals gave a linear graph. The 3-D surface plots showed the relationship between the factors and responses of the designed experiments. In the study, temperature, time, inhibitor concentration, and medium concentration were the considered factors while corrosion rate, inhibition efficiency, and surface coverage were the expected responses. The results are arranged in Table 5 . Table 5 RSM result of the corrosion inhibition of steel in HCl by NH. Std Runs Factor 1; Tempt. °C Factor 2: Inhibit conc. Factor 3; medium (M) Response 1; corrosion rate Response 2: inhibitor Response 3: surface 15 1 45.00 6.00 0.30 1.01 98.19 0.98 14 2 45.00 6.00 0.30 1.01 98.19 0.98 13 3 45.00 6.00 0.30 1.01 98.19 0.98 6 4 60.00 6.00 0.10 0.67 99.57 0.99 3 5 30.00 10.00 0.30 0.67 96.21 0.96 16 6 45.00 6.00 0.30 1.01 98.19 0.98 2 7 60.00 2.00 0.30 3.03 98.05 0.98 1 8 30.00 2.00 0.30 1.68 90.5 0.91 11 9 45.00 2.00 0.50 3.88 97.51 0.98 12 10 45.00 10.00 0.50 1.19 99.23 0.99 4 11 60.00 10.00 0.30 0.84 99.46 0.99 8 12 60.00 6.00 0.50 2.86 98.16 0.98 5 13 30.00 6.00 0.10 0.67 95.15 0.95 17 14 45.00 6.00 0.30 1.01 98.19 0.98 7 15 30.00 6.00 0.50 1.68 93.76 0.94 9 16 45.00 2.00 0.10 1.01 97.64 0.98 10 17 45.00 10.00 0.10 0.67 94.21 0.94 Further analysis of data was addressed in terms of ANOVA, mathematical model, and optimization. The ANOVA of Table 6 helped in identifying the model’s significance terms. The power of the variable was used to confirm the quadratic models. The models displayed the inhibition efficiency as a function of the factors. The interactive behavior of the factors was also identified. Table 6 ANOVA for the corrosion Inhibitor by NH. Source model Sum of squares Df Mean square F- value p-value Prob > F 14.47 9 1.61 498.69 < 0.0001 Significant A- Temperature 0.91 1 0.91 282.56 < 0.0001 B- Inhibitor conc 4.85 1 4.85 1504.38 < 0.0001 C- Medium conc. 5.43 1 5.43 1683.26 < 0.0001 A 2 0.11 1 0.11 35.01 0.0006 B 2 0.61 1 0.61 189.77 < 0.0001 C 2 0.37 1 0.37 114.58 < 0.0001 AB 0.35 1 0.35 107.94 < 0.0001 AC 0.35 1 0.35 107.94 < 0.0001 BC 1.38 1 1.38 428.10 < 0.0001 Residual 0.023 7 3.225E-003 Lack of Fit 0.023 3 7.525E-003 Pure Error 0.000 4 0.000 Cor Total 14.50 16 Std. Dev. 0.057 R-Squared 0.9984 Mean 1.41 Adj R-Squared 0.9964 C.V. % 4.04 Pred R-Squared 0.9751 PRESS 0.36 Adeq Precision 75.163 A mathematical model for the corrosion inhibition was given in Eq. 4. IE = + 98.19 + 2.45A (4) The optimum parameters for corrosion inhibition of mild-steel as given in Table 7 show values as concentration 10g/l, temperature 50 0 C, time 6hr and efficiency 99.13% for the mild-steel in acidic medium with NH as inhibitor. Table 7 Optimum parameters of the NH Inhibitor. Molar quantity NH Quantity mg/L Temp. o C Inhibition efficiency (%) 0.5M HCl 10 50 99.13 This high value efficiency indicates that natural honey is a good corrosion controller of metal surfaces. This result was validated in Table 8 by conducting additional experiments. Table 8 Result validation for the corrosion inhibitor NH. Molar quantity NH quantity mg/L Temperature o C Pred. efficiency (%). Measured efficiency (%). Percentage error (%). 0.5M HCl 10 50 99.13 99.52 0.39 3.15 Quantum Simulation (Computational) Studies Result Table 9 shows the calculated value of quantum chemical properties of NH, and Table 10 shows calculated charges and indices for attacks by NH molecule. When the values of E LUMO were lesser, it signified a higher ability of electrons to accept molecule [ 39 – 40 ]. Similarly, low values of the energy gap, ΔE, gave good effectiveness of the inhibition as the energy reduction leads in terminating electrons. Calculated values of energies (of frontier molecular orbitals) were − 6.600 and − 6.512 e V. The High value of this energy shows NH’s ability to give out electrons at the surface of mild-steel. The ΔE-value of (0.088 eV) obtained shows the NHs’ high reactivity on the surface. Table 9 Value of quantum chemical properties of (inhibitor) natural honey Property Natural honey eV E HOMO (e V) -6.600 E LUMO (e V) -6.512 E LUMO−HOMO (e V) 0.088 F + (Mulliken) 0.289 F − (Mulliken) 0.375 Atomic charge 0.937 Table 10 shows the calculated value of quantum chemical properties of NH, and Table 11 shows a calculated Mulliken atomic charges and Fukui indices for nucleophilic (F + ) and electrophilic (F - ) attacks by NH molecule. Table 10 Mulliken atomic charges and Fukui indices for natural honey molecule Atom Atomic Charge F + (nucleophilic) F - Electrophilic C (1) 0.471 0.000 0.007 C (2) 0.078 0.001 0.003 C (3) -0.035 0.000 0.014 C (4) -0.058 0.000 0.006 C (5) 0.178 0.001 0.002 C (6) -0.049 0.001 0.016 O (7) -0.458 0.000 0.037 O (8) -1.193 0.001 0.296 H (9) 0.445 0.000 0.001 H (10) 0.390 0.000 0.001 H (11) 0.545 0.000 0.000 O (12) -0.266 0.001 0.013 O (13) -1.068 0.000 0.010 H (14) 0.545 0.000 0.004 H (15) 0.194 0.000 0.000 O (16) -0.273 0.001 0.084 O (17) -1.084 0.002 0.375 H (18) 0.499 0.000 0.025 H (19) 0.732 0.000 0.001 O (20) -0.884 0.001 0.007 O (21) -0.807 0.001 0.028 O (22) -1.215 0.000 0.012 C (23) -0.255 0.004 0.011 H (24) 0.141 0.000 0.000 H (25) 0.383 0.000 0.003 O (26) 0.646 0.001 0.014 O (27) 0.937 0.001 0.014 H (28) 0.638 0.000 0.006 H (29) 0.285 0.000 0.002 O (30) -0.344 0.006 0.000 C (31) 0.845 0.010 0.000 H (32) 0.394 0.001 0.000 C (33) 0.113 0.003 0.000 C (34) 0.864 0.011 0.0000 C (35) 0.057 0.006 0.000 C (36) 0.023 0.011 0.000 C (37) 0.332 0.005 0.000 O (38) -0.414 0.049 0.000 O (39) -0.121 0.158 0.001 O (40) 0.046 0.289 0.001 O (41) 0.012 0.276 0.001 O (42) -0.812 0.134 0.001 O (43) -0.268 0.000 0.00 C (44) 0.583 0.002 0.000 H (45) 0.317 0.000 0.000 H (46) 0.613 0.001 0.000 O (47) -0.516 0.000 0.000 H (48) 0.656 0.000 0.000 H (49) 0.329 0.000 0.000 H (50) 0.525 0.000 0.000 H (51) 0.332 0.002 0.000 O (52) -0.202 0.005 0.000 3.16 Molecular Dynamics Simulation Results Results of binding ( \(\:{E}_{bind}\) ) and total ( \(\:{E}_{total}\) ) energies calculated with Eq. 5 [ 37 – 40 ] were arranged in Table 11 : $$\:{E}_{bind}=\:{E}_{total}-({E}_{inh}+\:{E}_{metal})$$ 5 Values indicate that binding energy was negative, which implied an exothermic reaction. Increases in binding energy made adsorption easier and enhanced efficiency. Table 11 Molecular dynamics simulation results of binding and total energies Energy \(\:{E}_{bind}\) \(\:{E}_{total}\) Natural honey quantity -171.82095 -2146.517620. 3.17 SEM The Analysis Result was shown in plate 2 (a to f). [SEM images for ‘a’ unexposed mild steel in 0.5 M HCl; b, c, and d exposed mild steel in blank solution at (2, 4, 6,) g/L of NH respectively, and e and f exposed mild steel in 0.5 M HCl containing (8 and 10) g/L natural honey at 50°C for 6 h]. Now, image ‘2a’ is shown expanded as an example of the rest. 3.2 DISCUSSION FTIR spectrum with peaks show absorbance on the vertical axis and frequency on the horizontal axis of the NH [ 31 – 32 ]. Analysis of NH revealed the presence of C-H bend, =C-H bend, RCH-C’ R’’, C = O stretch, C = C-CH (R) OH, C-O stretch, Ro-O-H, N-H blend, R-C (O)-NH-R, C ≡ N stretch, carboxylic acids, C-H stretch of C = O aldehydes, O-H stretch carboxylic acid, N-H stretch amines-primary, hydrogen-bonded O-H stretch, carboxylic acids and N-H symmetric stretch amines. Curves for the mild-steel samples in 0.5 M hydrochloric acid without and with natural honey exhibit active dissolution, as in Fig. 1 , that shifted E corr in an anodic direction. This anodic polarization was more pronounced than the cathodic, indicating that corrosion was under anodic control at all NH concentrations. However, at high concentrations, NH abridged de-polarization effect and subsequently retards anodic dissolution and cathodic reactions. Its presence moved the E corr towards pessimistic potential at high and low concentrations. This proved that NH hindered the discharging of hydrogen gas and the anodic dissolution of metal. While NH was added, it echoed the performance of inhibition potential [ 33 ]. Evaluating the E corr value, the inhibitor was viewed as cathodic or anodic when displacement was greater than 85 mV. However, it became a mixed inhibitor when displacement was below 85 mV. Another proof was the NH’s reduction of current densities in cathodic and anodic regions. The test was performed at the open circuit potential (OCP). High frequency intercept with real axis in the plots was ascribed to solution resistance \(\:{\varvec{R}}_{\varvec{s}}\) and low frequency to charge transfer resistance \(\:{\varvec{R}}_{\varvec{c}\varvec{t}}\) . The numerical values of impedance parameters are arranged in Table 2 . Values of \(\:{\varvec{C}}_{\varvec{d}\varvec{l}}\) decreased [ 34 ] due to a decrease in dielectric constant and/or an increase in double-layer thickness. Slight variations in values of corrosion rate and efficiency were ascribable to different techniques applied. Incorporation of NH into mild-steel coupons dissolved in 0.5 M HCl at variable temperatures, controlled weight-loss as it increased temperatures. See Fig. 4 . Table 4 shows the variation effects of different NH concentrations as inhibitors at different temperatures. The rate of corrosion decreased with temperature, and inhibition action increased, indicating a reduction in temperature. A stable corroded surface was formed and thereby prevented further diffusion of diluted acid. Observed increment in concentration corresponds to increment in efficiency. Hence, maximum efficiency is 99.13% at 10 g/L and 50 o C (see Table 4 ). Graphical analysis of the efficiency of honey on mild steel in acid was shown in Fig. 6 . This study was observed to follow the Langmuir adsorption isotherm, and the observations were in agreement with previous studies by [ 35 – 36 ]. They applied the molecular simulation studies to optimize the adsorption structures of triazole derivatives and found that adsorption of the inhibitors on the mild steel surface in the acid solution obey the Langmuir isotherm. Further analysis of data was addressed in ANOVA, mathematical model, and optimization. From ANOVA, F- F-value of 498.69 implied significant model (Table 6 ). There was only a 0.01 chance that a value this large could occur due to noise. Values of “Prob > F” \(\:<\) 0.5000, and greater than 0.1000 indicated that model terms (A, B, C, A 2 , AB, AC, BC) were significant. “Pred R-Square” of 0.9751 was in reasonable agreement with “Adj R-Squared” of 0.9964; the difference being less than 0.2. “Adequate Precision” measures produced a ratio of 75.163, indicating adequate signal for this model to navigate the design space. Quantum chemical calculations based on the density functional theory DFT method were performed on NH used as corrosion inhibitor for mild-steel in HCl-acid media to determine the relationship between the molecular structure of NH and inhibition efficiency. This method was an acceptable tool to assess the inhibitive performance of different materials. It was used as a channel to tackle experimental work on corrosion by [ 36 – 37 ]. The structural parameters, such as the frontier molecular orbital energy \(\:{E}_{HOMO}\) (highest occupied molecular orbital), \(\:{E}_{LUMO}\) (lowest unoccupied molecular orbital) and energy gap (ΔE = \(\:{E}_{LUMO}\) – \(\:{E}_{HOMO}\) ) were examined [ 38 ]. The charge distribution of the studied inhibitor, the absolute electronegativity (χ) values, and the fraction of electrons (ΔN) transferred from inhibitor to mild steel were also calculated and correlated with the inhibition efficiency. The movement of electrons led to the adsorption process, following the theory of chemical reactivity. Large vales of E HOMO show a huge aptitude of molecule to donate electrons to ease adsorption process, thus, specifying better performance of inhibitor. At lesser values of E LUMO , a higher ability of electrons to accept molecule was implied [ 39 – 40 ]. Similarly, low energy gap, ΔE of 0.088 eV indicates that NH had high adsorption reactivity on the surface of mild-steel. Thus, ΔE agreed with the result obtained elsewhere [ 40 ]. Adsorption sites were activated when NH electron structure and molecular orbit were assessed. DFT and electronic structure programs DMol 3 were adopted for simulation, and Mulliken population analysis was used in analyzing it. Local reactivity regarding nucleophilic and electrophilic were examined with Fukui indices to review active regions as in plate 1. Differences in the morphology of metals’ surface were presented in plate 2 (a-f). Electron micrographs revealed a strongly damaged surface owing to corrosion, and was reduced in the presence of inhibitor. These micrographs have close correlations with results earlier obtained in previous studies by [ 40 – 41 ]. 4.0 CONCLUSION The correlation between the quantum chemical parameters and inhibition efficiency of NH was investigated using density functional theory DFT calculation. The inhibition efficiency of the inhibitor is closely related to the quantum chemical parameters, E HOMO , E LUMO , \(\:\varDelta\:\) E (energy-gap). The inhibitor has a considerable tendency for the protonation, the process which is a downhill exothermic reaction. The value of adsorption energy E ads , is negative, which means that the adsorption could occur spontaneously. NH had the highest inhibition efficiency because it had the highest E HOMO energy value, and it was most capable of offering electrons. Molecular dynamic simulations were performed to study the adsorption behavior of the inhibitor on the mild-steel surface, and it was observed that the adsorption occurs mostly through the lone pair of electrons of the hetero-atoms and p-electrons of the NH. This study displays a good correlation between the theoretical and experimental data, which confirms the reliability of the quantum chemical methods to study the inhibition of corrosion of mild-steel surface. The anodic polarization was more pronounced than the cathodic, indicating that corrosion was under anodic control at all NH concentrations. The reduction of current densities, polarization measurement, and evaluation of E corr value show NH as a good corrosion controller. The percentage efficiency of NH increased with the concentration and temperature. The highest, 99.13%, was obtained at a concentration of 10 mg/L with a temperature of 50 C. This study was observed to follow the Langmuir adsorption isotherm. Therefore, NA was a good corrosion inhibitor of mild steel in 0.5 M HCl surroundings. Declarations Author Contributions: Ezeamaku Uche Luvia: Writing-Review and Editing, Investigation, Visualization, Formal Analysis, Software. Onyechere Chigozie: Writing-original draft, Data curation, Conceptualization. Okechukwu Dominic Onukwuli: Supervision, Project administration, Methodology. Obibuenyi, Ifeanyi John: Writing-Review and Editing, Investigation, Validation, Declaration of Competing Interest: The authors declare that they have no known competing financial interests or personal relationships that could have influenced the work in this study. Funding Statement: All authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript. Declaration of Ethical Statement: This research received ethical approval and complied with the guidelines and regulations of the studies. Informed consent was obtained from all participants. There were no human participants involved in the study. Therefore, research has been conducted with the highest standards for rigor and integrity. The article study is original. This work has not been submitted elsewhere and is not under consideration for publication elsewhere. The work does not include libelous, defamatory, or unlawful statements. There was no third-party material(s) included. Proof of consent has been obtained for any named individuals or organizations. Authorship has been agreed upon before submission, and no one has been gifted authorship or denied credit as an author (ghost authorship). Data Availability: No data was used in this article. However, the data that support the findings of this study are available from the corresponding author, [I. J. O], upon reasonable request. 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A review on the assessment of polymeric materials used as corrosion inhibitor of metals and alloys. International Journal of Industrial Chemistry, 4(2), 1–9. (2013). Arukalam, I. O. et al. Adsorption and inhibitive properties of hydroxypropyl methylcellulose on the acid corrosion of mild steel. International Journal of Applied Sciences and Engineering Research , 2(6), 613–629. (2013). Umoren, S. A. Polymers as corrosion inhibitors for metals in different media–A review. The Open Corrosion Journal , 2, 175–188. (2009). Ezeamaku, U. L. et al. Investigating the Inhibitive Powers of Orange Leaf Extract in Corrosion Studies of Mild Steel Metal in HCl. IOSR Journal of Applied Chemistry , 12(12), 59–66. (2019). Ezeamaku, U. L. et al. Examining the Effectiveness of Bitter Leaf Extract in Fighting Corrosion. IOSR J. Appl. Phys. 12 (1), 40–44 (2020). Arukalam, I. O. et al. Experimental and theoretical studies of hydroxyethyl cellulose as inhibitor for acid corrosion inhibition of mild steel and aluminum. The Open Corrosion Journal , 6, 1–10. (2014). Oguzie, E. E. et al. Understanding corrosion inhibition mechanisms - Experimental and theoretical approach. RSC Advanced , 1, 866–873. (2011). Vinod, K. P. et al. Inhibition of mild steel corrosion in hydrochloric acid by the seed husk extract of Jat-ropha Curcas . J. Mater. Environs Sci. 1 , 119–128 (2010). Bereket, G. A. et al. Inhibition of corrosion of low carbon steel in acidic solution by selected polyelectrolytes and polymers. Anti Corros. Method Mater. 50 , 422–535 (2003). Ashassi, H. et al. Corrosion inhibition of carbon steel in hydrochloric acid by some polyethylene glycols. Electrochem. Acta . 51 , 3848–3854 (2006). Umoren, S. A. et al. Polyethylene glycol and poly vinyl alcohol as corrosion inhibitors for aluminum in acidic medium. J. Appl. Polym. Sci. 105 , 3363–3370 (2007). Duubey, A. K. & Singh, G. Corrosion inhibition of mild steel in sulphuric acid solution by using polyethylene glycol methyl ether (PEGME). Port Electrochemical Acta , 25: 221–235. (2007). Umoren, S. A. Inhibition of aluminum and mild steel corrosion in acidic medium using Gum Arabic. Cellulose 15 , 751–761 (2008). Nwanonenyi, S. C. et al. Corrosion inhibition of mild steel in sulphuric acid environment using millet starch and potassium iodide. Int. Res. J. Pure Appl. Chem. 12 , 1–21 (2016). Nwanonenyi, S. C., Ogbobe, O. & Oguzie, E. E. Protection of mild steel corrosion in sulphuric acid environment using wheat starch. Int. J. Eng. Technol. 10 , 11–21 (2017). Cruz, J., Pandiyan, T. & Garcia-Ocha, E. A new inhibitor for mild steel: electrochemical and DFT studies. J. Electro-anal Chem. 583 , 8–16 (2005). Khaled, K. F. Corrosion control of copper in nitric acid solutions using some amino-acids: a combined experimental and theoretical study. Corros. Sci. 52 , 3225–3234 (2010). Chike-Onyegbula, C. O. et al. Biodegradable polymer drilling mud prepared from guinea corn. J. Brew Distil. 2912, 3: 6–14. Satapathy, A. K. et al. Corrosion inhibition by Justica gendrausssa plant extract in hydrochloric acid solution. Corros. Sci. 51 , 2848–2856 (2009). E. E. Oguzie. Corrosion inhibition of aluminum in acidic and alkaline media by sanservieria trifasciata extract. Corros Sci. 49: 1523 ̶ 1539. (2007). Oguzie, E. E. et al. Adsorption and corrosion inhibiting effect of dcryodisedulis extract on low carbon steel corrosion in acidic media. J. Colloid Interface Sci. 349 , 283–292 (2010). Furniss, B. S. et al. Vegel’s Textbook of Practical Organic Chemistry, 5th edition, Longman Group, UK, 1412–1422. (2009). Eddy, N. O. et al. Inhibitive and adsorption properties of ethanol extract of Hibiscus sabdariffa Calyx for the corrosion of mild steel in 0.1 M HCl. Green Chem. Lett. Rev. 5 (1), 43–53 (2012). Solomon, M. M. et al. Inhibitive and adsorption behavior of carboxymethyl cellulose on mild steel corrosion in sulphuric acid solution. Corros. Sci. 52 , 1317–1325 (2010). Saviour, A. et al. Inhibition of mild steel corrosion in HCl solution using Chitosan. Springer + Bus. media Dordrecht: Cellulose . 20 (5), 2529–2545 (2013). Ouariachi, E. I. et al. Adsorption properties of Rosmarinus of ficinalis oil as green corrosion inhibitors on C38 steel in 0.5 M H 2 SO 4 . Acta Metal. Sin. (Engl. Lett.), 23 (1), 13–20. (2010). Rodriguez-Valdz, L. M. et al. Computational simulations of the molecular structure and corrosion properties of amidoethyl, aminoethyl and hydroxy-ethly imicazolines inhibitors. Corros. Sci. 48 , 4053–4064 (2006). Ju, H. et al. Aminic nitrogen-bearing polydentate Schiff base compounds as corrosion inhibitors for iron in acidic media: a quantum chemical calculation. Corros. Sci. 50 , 865–871 (2008). Rodriguez Valdez, L. M. et al. Computational simulation of the molecular structure and properties of heterocyclic organic compounds with possible corrosion inhibition properties. J. Mol. Struct. THEOCHEM . 713 , 65–70 (2005). K. F. Khaled. Molecular stimulation, quantum chemical calculations and electrochemical studies for the inhibition of mild steel by triazoles Electro-chemical Acta, 53 :3484–3492. (2008). Issa, R. M. et al. Quantum chemical studies on the inhibition of corrosion of copper surface by substituted uracils. Appl. Surf. Sci. 255 , 2433–2441 (2008). Oguzie, E. E. et al. Biomass extracts for materials preparation: corrosion inhibition of mild steel in acidic media terminalia chebula extracts. Chem. Eng. Commum . 201 , 790–803 (2013). Bartley, J. et al. Computer simulation of the corrosion inhibition of copper in acidic solution by alkyl esters of 5-carboxylbenzotriazole. Corros. Sci. 45 , 81–96 (2003). Loto, C. A. & Popoola, A. P. I. Plant extract corrosion inhibition of Aluminum alloy in H 2 SO 4 . Can. J. Pure Appl. Sci. 65 , 299–308 (2012). Emerole, J. C. et al. Response Surface methodology and experimental evaluation of the inhibitory properties of corn leaf extract for aluminum corrosion in acid media (Ani-Corrosion Methods and Materials, 2024). Yüce, A. O. Corrosion Inhibition Behavior of Robinia pseudo-acacia Leaves Extract as an Eco-Friendly Inhibitor on Mild Steel in Acidic Media. Met. Mater. Int. 26 , 456–466. https://doi.org/10.1007/s12540-019-00509-7 (2020). Plates Plates 1 and 2 are available in the Supplementary Files section. Additional Declarations No competing interests reported. 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Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5727302","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":450093178,"identity":"fde20e8f-6d62-45ff-927c-9a355c733f42","order_by":0,"name":"Ifeanyi John Obibuenyi","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIiWNgGAWjYBACxgYeECGRAOYlVAAJZuYGUrScAWlhxK+FgQGshQGihbENYgxeDcztvccefNxhkWdwvPeYxMN5tdH87UAtPyq24XZYz7l0w5lnJIoNzpxLk0jcdjx3xmHGBsaeM7dxa5mRYybN2yaRuOFGjhlQy7HcBqAWZsY2YrTcfwPUMudY7nzitdzgAWppqMndQFBLzxkzSZBfJM/kGFskHDuQuxGo5SA+vxi295hJfNxRl8d3/IzhzR81dbnzzh8++OBHBR4tDQg2iwQDw2Ew6wBO9UAgj8Rm/sDAUIdP8SgYBaNgFIxQAACUQ192EZjyUAAAAABJRU5ErkJggg==","orcid":"","institution":"Madonna University, Nigeria, Akpugo Campus, Enugu State, Nigeria.","correspondingAuthor":true,"prefix":"","firstName":"Ifeanyi","middleName":"John","lastName":"Obibuenyi","suffix":""},{"id":450093179,"identity":"c5081366-8091-4619-aa2b-78f87e5f709f","order_by":1,"name":"Uche Luvia Ezeamaku","email":"","orcid":"","institution":"Federal University of Technology Owerri","correspondingAuthor":false,"prefix":"","firstName":"Uche","middleName":"Luvia","lastName":"Ezeamaku","suffix":""},{"id":450093180,"identity":"00fd36b0-2a59-48f2-a7ab-5a6af703a13a","order_by":2,"name":"Chigozie Onyechere","email":"","orcid":"","institution":"Federal University of Technology Owerri","correspondingAuthor":false,"prefix":"","firstName":"Chigozie","middleName":"","lastName":"Onyechere","suffix":""},{"id":450093181,"identity":"91e07920-c557-4bae-8734-9aa04275512c","order_by":3,"name":"Okechukwu Dominic Onukwuli","email":"","orcid":"","institution":"Nnamdi Azikuwe University, Awka,","correspondingAuthor":false,"prefix":"","firstName":"Okechukwu","middleName":"Dominic","lastName":"Onukwuli","suffix":""}],"badges":[],"createdAt":"2024-12-28 17:53:05","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5727302/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5727302/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":82044739,"identity":"d4f21f64-d4e7-4495-90da-b3d20892fc70","added_by":"auto","created_at":"2025-05-06 09:31:32","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":60597,"visible":true,"origin":"","legend":"\u003cp\u003eThe FTIR spectrum of the NH\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5727302/v1/5a41df53546563a55c6f4594.jpg"},{"id":82048726,"identity":"48278a40-0a3d-4577-b150-b26a379f46c8","added_by":"auto","created_at":"2025-05-06 09:47:32","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":44612,"visible":true,"origin":"","legend":"\u003cp\u003ePotentio-dynamic polarization curves for mild steel in 0.5 M HCl in the presence and absence of NH\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5727302/v1/f5b371b51bda978efb3b25d8.jpg"},{"id":82046681,"identity":"334ec401-0a51-4b5b-bcc9-d545a567b6ae","added_by":"auto","created_at":"2025-05-06 09:39:32","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":35397,"visible":true,"origin":"","legend":"\u003cp\u003eNyquist plots for mild-steel in 0.5 M HCl in the absence and presence of NH\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5727302/v1/4e4a472da41efd3e3eca5968.jpg"},{"id":82044744,"identity":"71a2e855-5a39-479f-b905-57abc4cf3877","added_by":"auto","created_at":"2025-05-06 09:31:33","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":38551,"visible":true,"origin":"","legend":"\u003cp\u003eGravimetric measurement of mild steel in 0.5 M HCl and NH\u003c/p\u003e","description":"","filename":"4.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5727302/v1/e12e519734b957e8c108461d.jpg"},{"id":82048727,"identity":"2d37eb08-2772-465f-a413-dcc556ecb068","added_by":"auto","created_at":"2025-05-06 09:47:33","extension":"jpg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":34726,"visible":true,"origin":"","legend":"\u003cp\u003eVariation of inhibition efficiency with different concentrations of NH at different temperatures.\u003c/p\u003e","description":"","filename":"5.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5727302/v1/b484d6c4797afa8cbfbaa5fa.jpg"},{"id":82046683,"identity":"3d762666-83ed-4d3f-92d8-0b645f0e0c3e","added_by":"auto","created_at":"2025-05-06 09:39:33","extension":"jpg","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":47026,"visible":true,"origin":"","legend":"\u003cp\u003eIE (%) of natural honey as corrosion inhibitor of steel in HCl (a) normal plot of residuals versus studentized residuals IE (%), (b) IE (%) versus inhibitor concentration and temperature, (c) IE (%) versus medium concentration and temperature, (d) IE (%) versus medium concentration and inhibitor concentration.\u003c/p\u003e","description":"","filename":"6.jpg","url":"https://assets-eu.researchsquare.com/files/rs-5727302/v1/ffa03b0ffcae8c42fd46dab8.jpg"},{"id":82051652,"identity":"70ff260d-2c72-455f-8c1a-a704dc697472","added_by":"auto","created_at":"2025-05-06 10:03:39","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1722626,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5727302/v1/85711463-1119-4ad4-8f42-2b5bf551153d.pdf"},{"id":82044748,"identity":"552edb7d-7d47-4fa0-a4dc-4b62f796eb8a","added_by":"auto","created_at":"2025-05-06 09:31:33","extension":"docx","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":4824912,"visible":true,"origin":"","legend":"","description":"","filename":"Plates.docx","url":"https://assets-eu.researchsquare.com/files/rs-5727302/v1/8624c8bbe41fb7e6b704b39b.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"The Role of Natural Honey as a Corrosion Inhibitor for Mild Steel in Hydrochloric Acid","fulltext":[{"header":"INTRODUCTION","content":"\u003cp\u003eCorrosion is a global problem and an inevitable matter of great concern that requires constant attention to resolve. Indeed, corrosion leads to the depletion of our natural resources, especially in the metal industries [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Aggressive environments caused by corrosion in the presence of acids lead to the instability of metal structures and, hence, are most unfriendly to metals. The effect of this development often leads to serious problems such as surface dulling, high operational costs and maintenance, product contamination, downtime, loss of valuable products, and effects of safety reliability [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eTo solve the problem of corrosion, different techniques were employed, including the use of suitable corrosion inhibitors [\u003cspan additionalcitationids=\"CR4 CR5\" citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e] and [\u003cspan additionalcitationids=\"CR8 CR9 CR10\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Metals were separated from corrosive agents while compounds containing inhibiting molecules were adsorbed at the surface of the metal where protective barrier was formed [\u003cspan additionalcitationids=\"CR13\" citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The obvious advantageous need and use of steel and their alloys lead to the quest for solutions to corrosion problems [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. Some of these properties are good mechanical strength, high thermal conductivity, good electrical properties, etc.\u003c/p\u003e \u003cp\u003ePrevious studies have investigated the use of natural honey as a corrosion inhibitor in 0.5 M HCl media, with results showing that honey can effectively act as a corrosion inhibitor for metals like carbon steel. The use of honey also demonstrated a significant reduction in the corrosion rate when added to the acidic solution. The inhibition mechanism is generally attributed to the adsorption of honey components onto the metal surface, forming a protective layer against further corrosion. The highest rate of corrosion inhibition (93.5%) was attained at a concentration of 1800 ppm with an increase in the concentration of the extract [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. Many other researchers have also reported their findings on the use of both natural and synthetic polymers to inhibit the corrosion of metals in aggressive environments [\u003cspan additionalcitationids=\"CR17 CR18 CR19 CR20 CR21\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Studies have also shown that natural honey can achieve high corrosion inhibition efficiencies in 0.5 M HCl, with the effectiveness often depending on the concentration of honey used.\u003c/p\u003e \u003cp\u003eIn this study, natural honey (NH), a dependable inhibitor, was used to control the corrosion of mild steel and its alloys in a 0.5 M hydrochloric acid environment. NH is friendly, low costing, and readily available, hence its choice in mitigating the corrosion menace. Key findings from this research showed that the inhibition efficiency was 99.13% at 10 g/L of NH and 50 \u003csup\u003eo\u003c/sup\u003eC. Detailed knowledge of characteristic inhibition-intake at the molecular level of the experiment using the inhibitor was provided with the aid of Quantum Simulation (Computational) Studies. One such theory is the density functional theory (DFT). This is useful means of evaluating the inhibitive efficiency of corrosion of different materials to predict functional centers of adsorption [\u003cspan additionalcitationids=\"CR24\" citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e"},{"header":"2.1 MATERIAL","content":"\u003cp\u003eMild-steel specimen was purchased from local market. Other material include thread, desiccator, Fourier transform infrared spectrophotometer (\u003cb\u003eshimadzu\u003c/b\u003e, model: IR affinity \u0026ndash; 1; s/n A2137470136 SI), PARC-23, electrolytic cell, power suite software, weighing balance, thermometer, thermostatic water bath, capacity beakers, glass rod, hooks, RSM design expert software, DFT electronic structure programs DMol\u003csup\u003e3\u003c/sup\u003e as contained in the Material Studio 7.0 software program, and XL-30FEG scanning electron microscope. Consumable materials include ethanol, distilled water, acetone, standard-grade HCl, NH, etc. NH was purchased from the dealers, while others were assessed from the institution\u0026rsquo;s laboratory.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003e2.2 METHODS\u003c/h2\u003e \u003cp\u003eThe mild-steel specimen with the following compositions: 0.02% Si; 0.05% C; 0.18% Mn; 0.02% Cu and 99.73% Fe, was cut into 2 x 2 x 2 cm\u003csup\u003e3\u003c/sup\u003e dimensions and pressed mechanically. The coupons were degreased with absolute ethanol, washed, dried with acetone, and kept in desiccators. Undiluted 0.5 M hydrochloric acid was provided. Various concentrations (2, 4, 6, 8, 10) g/L of NH were prepared. The blank acid was prepared using distilled water inhibited with (50 mg/L and 1000 mg/L) NH respectively. This was similar to the method used in the processing of guinea corn by [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFTIR analysis of NH was performed at the Energy Center of the University of Nigeria, Nsukka. The spectroscope simultaneously collected the high-spectral-resolution data over a wide range and converted the raw data into an actual spectrum.\u003c/p\u003e \u003cp\u003eThe cylindrical electrolytic cell glass was used in the polarization measurement. Electrodes were connected to the electrochemical cell with the aid of a lugg-in capillary at room temperature (30\u0026thinsp;\u0026plusmn;\u0026thinsp;1\u003csup\u003eo\u003c/sup\u003eC). All measurements were performed, and the steady-state value OPC was obtained after 30 minutes of immersion. The study was done at a potential range of approximately 250 mV versus corrosion potential at a scan rate of 0.33 mV per second [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. Extrapolation of data was carried out with the Power Suite software, and the system\u0026rsquo;s reproducibility was verified at an average of three attempts.\u003c/p\u003e \u003cp\u003eSpecimens were carefully prepared and immersed in 200 ml test solutions at 28 \u003csup\u003eo\u003c/sup\u003e C while performing the gravimetric measurement. They were then suspended in 250 ml test solutions with glass rods and hooks. The tests were conducted three times to ensure reproducibility in aerated solutions. After establishing weight loss, specimens were retrieved at 24-hour intervals for 120 hrs. The thermostatic water bath was maintained at 30 \u0026deg; C, 40 \u0026deg; C, 50 \u0026deg; C, and 60 \u0026deg; C for 6 hours. Weight losses were recorded as an average value of three determinant coupons. The corrosion rate of mild steel in 0.5 M HCl solution with NH was calculated with the following Eq.\u0026nbsp;1 [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]:\u003c/p\u003e \u003cp\u003eCorrosion rate, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:x=\\frac{876000\\varDelta\\:\\text{W}}{{\\rho\\:}\\text{A}\\text{t}}\\)\u003c/span\u003e\u003c/span\u003e (1)\u003c/p\u003e \u003cp\u003ewhere, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\rho\\:\\)\u003c/span\u003e\u003c/span\u003e, ΔW, A and t are respectively density, weight loss, area, and time.\u003c/p\u003e \u003cp\u003eThe percentage inhibition-efficiency was obtained with Eq.\u0026nbsp;2 [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]:\u003c/p\u003e \u003cp\u003e \u003cspan class=\"InlineEquation\"\u003e \u003cspan class=\"mathinline\"\u003e\\(\\:\\%\\:I.E=\\{1-(\\frac{{R}_{ct}}{{R}_{ct\\:inh}}\\left)\\right\\}\\:\\)\u003c/span\u003e \u003c/span\u003e x 100 (2)\u003c/p\u003e \u003cp\u003ewhere \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{R}_{ct}\\)\u003c/span\u003e\u003c/span\u003eand \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{R}_{ct\\:inh}\\)\u003c/span\u003e\u003c/span\u003eare charge transfer resistances.\u003c/p\u003e \u003cp\u003eEquation \u003cspan refid=\"Equ1\" class=\"InternalRef\"\u003e3\u003c/span\u003e was used in determining \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\theta\\:\\)\u003c/span\u003e\u003c/span\u003e (degree of surface coverage) [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e]:\u003cdiv id=\"Equ1\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ1\" name=\"EquationSource\"\u003e\n$$\\:\\theta\\:=\\:\\left[1-\\left(\\frac{C{R}_{pre}}{C{R}_{abs}}\\right)\\right]\\:x\\:100$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e3\u003c/div\u003e\u003c/div\u003e\u003c/p\u003e \u003cp\u003ewhere \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{CR}_{pre}\\)\u003c/span\u003e\u003c/span\u003e and \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{CR}_{abs}\\)\u003c/span\u003e\u003c/span\u003e are corrosion rates.\u003c/p\u003e \u003cp\u003eIn designing the experiments, RSM was used, and design matrices were obtained. Similarly, ANOVA was carried out, and factors coded\u0026thinsp;+\u0026thinsp;1 and \u0026minus;\u0026thinsp;1 were obtained.\u003c/p\u003e \u003cp\u003eQuantum simulations were performed with density functional theory DFT. Similarly, molecular dynamics simulation examined the interaction between inhibitor and corroding surface and investigated inhibitors\u0026rsquo; adsorption. Different low energy minima were sampled, and the global energy minimum was determined. Calculations were made at a fixed temperature of 25 \u003csup\u003e\u0026deg;\u003c/sup\u003e C. The process was quenched every 250 steps. The total energy (rigid adsorption energy) plus deformation energy and substrate energy at the surface was taken as zero. Finally, the surface morphology of specimens after immersion in 0.5 M HCl in the absence and presence of NH was analyzed with the scanning electron microscope (SEM).\u003c/p\u003e \u003c/div\u003e"},{"header":"3.0 RESULTS AND DISCUSSION","content":"\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e3.1 RESULTS\u003c/h2\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003e3.11 FTIR result on the NH\u003c/h2\u003e \u003cp\u003eFT-IR result of natural honey is presented in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. About 20 peaks are identified. The spectrum with peaks shows absorbance on the vertical axis and frequency on the horizontal axis. Analysis of NH revealed the presence of C-H bend, =C-H bend, RCH-C’ R’’, C = O stretch, C = C-CH (R) OH, C-O stretch, Ro-O-H, N-H blend, R-C (O)-NH-R, C ≡ N stretch, carboxylic acids, C-H stretch of C = O aldehydes, O-H stretch carboxylic acid, N-H stretch amines-primary, hydrogen-bonded O-H stretch, carboxylic acids and N-H symmetric stretch amines.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e\n\u003ch3\u003e3.12 Polarization Results\u003c/h3\u003e\n\u003cp\u003eThe results of the Polarization experiment to distinguish the effect of NH-inhibitor on corrosion of mild steel are arranged in Table \u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e. The NH was graded as an inhibitor which becomes cathodic or anodic when displacement was greater than 85 Mv and also a mixed inhibitor when displacement is below 85 mV. The electrochemical corrosion parameters, such as corrosion potential (E\u003csub\u003ecorr\u003c/sub\u003e), cathodic and anodic \u003cem\u003eTafel slopes\u003c/em\u003e (b\u003csub\u003ea\u003c/sub\u003e and b\u003csub\u003ec\u003c/sub\u003e), corrosion current (\u003cem\u003eI\u003c/em\u003e\u003csub\u003ecorr\u003c/sub\u003e), and inhibition efficiency (%IE), obtained by extrapolation of the Tafel lines, are also shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003ePolarization of NH inhibitor on corrosion of mild-steel.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuantity\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{-\\varvec{E}}_{\\varvec{c}\\varvec{o}\\varvec{r}\\varvec{r}}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003e[E vs. SCE (V)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eCorrosion current\u003c/p\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{I}}_{\\varvec{c}\\varvec{o}\\varvec{r}\\varvec{r}}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003e(µΑcm\u003csup\u003e-2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{b}}_{\\varvec{a}}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003e(m V dec \u003csup\u003e− 1\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{-\\varvec{b}}_{\\varvec{c}}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003e(m V dec \u003csup\u003e− 1\u003c/sup\u003e)\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eIE (%)\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0.5 M HCl\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-466.4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e183\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e102.6\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e122.7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e50 mg/L B\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-451.9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e22.5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e76.6\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e115.1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e87.7\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1000 mg/L B\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-461\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10.4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e73.8\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e104.2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e94.3\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eSimilarly, the Potentio-dynamic polarization curves plot for mild steel in 0.5 M HCl in the presence and absence of NH is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cdiv id=\"Sec8\" class=\"Section2\"\u003e \u003ch2\u003e3.13 Electrochemical impedance study of mild-steel corrosion in NH result\u003c/h2\u003e \u003cp\u003eNyquist plot for mild steel in 0.5 M HCl in the absence and presence of NH at various concentrations were shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. The plot shows that, the diameter of the capacitive loop and consequently the value of the charge-transfer resistance, \u003cb\u003eR\u003c/b\u003e\u003csub\u003e\u003cb\u003ect\u003c/b\u003e\u003c/sub\u003e increased with the concentration of inhibitor, which is an indication of the inhibitive action. In all cases, the semicircle corresponds to a capacitive loop. The semicircle radii depend on the inhibitor concentration. The diameter of the capacitive loop increased with increasing inhibitor concentration. The increase is more significant in fast green. The results show that \u003cb\u003eR\u003c/b\u003e\u003csub\u003e\u003cb\u003ect\u003c/b\u003e\u003c/sub\u003e values increased with an increase in inhibitor concentration. As \u003cb\u003eR\u003c/b\u003e\u003csub\u003e\u003cb\u003ect\u003c/b\u003e\u003c/sub\u003e is inversely proportioned to the corrosion current, it was used to determine the inhibitor efficiency.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eElectrochemical impedance parameters of mild steel in 0.5 M HCl in the absence and presence of honey at 30\u003csup\u003eo\u003c/sup\u003eC. The high frequency intercept with the real axis is ascribed to the solution resistance \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{R}}_{\\varvec{s}}\\)\u003c/span\u003e\u003c/span\u003e and the low frequency to the charge transfer resistance \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{R}}_{\\varvec{c}\\varvec{t}}\\)\u003c/span\u003e\u003c/span\u003e. It is obvious that the introduction of NH to the acidic environments increases the charge-transfer resistance, which inhibits the corrosion process. Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the numerical values of the impedance parameters of NH at 30\u003csup\u003eo\u003c/sup\u003eC.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eImpedance parameters of NH at 30\u003csup\u003eo\u003c/sup\u003eC.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eQuantity\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003esolution resistance \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{R}}_{\\varvec{s}}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003e(Ω cm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003echarge transfer resistance \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{R}}_{\\varvec{c}\\varvec{t}}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003e(Ω cm\u003csup\u003e2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eNH\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003eCapacitance\u003c/em\u003e,\u003c/p\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{C}}_{\\varvec{d}\\varvec{l}}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003cp\u003e(F cm\u003csup\u003e-2\u003c/sup\u003e)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eInhibition efficiency IE (%)\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0.5 M HCl\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.659\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e102.7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.89\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e6.908E-5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e50 mg/L NH\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.964\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e724.6\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.89\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e4.730E-5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e85.8\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{10}^{3}\\)\u003c/span\u003e\u003c/span\u003e mg/L NH\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3.527\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e789.4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e0.89\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e3.423E-5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e86.9\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003c/div\u003e\n\u003ch3\u003e3.14 Gravimetric Measurement Results\u003c/h3\u003e\n\u003cp\u003eThe weight loss concerning time and concentration additive was established at varying temperatures as in Table\u0026nbsp;\u003cspan refid=\"Tab3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. They were recorded as the average value of the difference between the initial and final weights of the three determinant coupons at a given time.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab3\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 3\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eWeight-loss of mild-steel in NH at varied temperatures.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNH Quantity\u003c/p\u003e \u003cp\u003eg/L\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e50\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e60\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBlank\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.160\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.350\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e-\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.020\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.026\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.032\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.020\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.024\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.012\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.015\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.017\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.009\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.011\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.008\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eThe gravimetric (weight-loss) measurement results in Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e indicate that NH acted as an effective inhibitor. The corrosion rate of respective, mild steel in 0.5, 0.3 and 0.1 M HCl solutions with and without NH were calculated with Eq.\u0026nbsp;1.\u003c/p\u003e \u003cp\u003eThe corrosion rate result in Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e indicates the formation of stable corroded surface due to reduced potency of dilute acid with temperature.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c9\" colnum=\"9\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c10\" colnum=\"10\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c11\" colnum=\"11\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c12\" colnum=\"12\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c13\" colnum=\"13\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab4\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 4\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eValues of corrosion rates (%) IE and degree of surface coverage (θ) in NH.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"13\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\" morerows=\"1\" rowspan=\"2\"\u003e \u003cp\u003eQuantity\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c5\" namest=\"c2\"\u003e \u003cp\u003eCorrosion rate\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c9\" namest=\"c6\"\u003e \u003cp\u003eInhibition efficiency (%)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colspan=\"4\" nameend=\"c13\" namest=\"c10\"\u003e \u003cp\u003eDegree of surface coverage (θ)\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e30\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e40\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e50\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e60\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e30\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e40\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003e50\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c9\"\u003e \u003cp\u003e60\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c10\"\u003e \u003cp\u003e30\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c11\"\u003e \u003cp\u003e40\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c12\"\u003e \u003cp\u003e50\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c13\"\u003e \u003cp\u003e60\u003csup\u003eo\u003c/sup\u003eC\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBLANK\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e26.94\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e58.93\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e155.23\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e155.23\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e―\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2 g/L\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.86\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e3.37\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e4.38\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e5.39\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e89.38\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e94.28\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e97.18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e96.53\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.89\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.94\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.97\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e0.97\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4 g/L\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.53\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e3.37\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e4.04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e91.87\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e95.71\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e97.83\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e97.4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.92\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.96\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e0.97\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6 g/L\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.68\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e2.02\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.53\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2.86\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e93.76\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e96.57\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e98.37\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e98.16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.94\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.97\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8 g/L\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.35\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.52\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.85\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e94.99\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e97.42\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e98.81\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e98.59\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.97\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10g/L\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1.01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e1.18\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e1.35\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.68\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e96.25\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e98.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c8\"\u003e \u003cp\u003e99.13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c9\"\u003e \u003cp\u003e98.92\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c10\"\u003e \u003cp\u003e0.96\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c11\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c12\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c13\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eInhibition Efficiency result in Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e and Table \u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e showed maximum efficiency 99.13% at 10 g/L of NH and 50\u003csup\u003eo\u003c/sup\u003eC.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe graphical analysis of inhibition efficiency of honey on the mild-steel in HCl environment are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e. Plots of Normal Residuals versus Studentized Residuals were used to test the significance of the model order. The residuals versus studentized residuals gave a linear graph. The 3-D surface plots showed the relationship between the factors and responses of the designed experiments.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn the study, temperature, time, inhibitor concentration, and medium concentration were the considered factors while corrosion rate, inhibition efficiency, and surface coverage were the expected responses. The results are arranged in Table\u0026nbsp;\u003cspan refid=\"Tab5\" class=\"InternalRef\"\u003e5\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c8\" colnum=\"8\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab5\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 5\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eRSM result of the corrosion inhibition of steel in HCl by NH.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"8\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStd\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eRuns\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eFactor 1;\u003c/p\u003e \u003cp\u003eTempt.\u003c/p\u003e \u003cp\u003e°C\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eFactor 2: Inhibit conc.\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eFactor 3; medium (M)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003eResponse 1; corrosion rate\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003eResponse 2: inhibitor\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c8\"\u003e \u003cp\u003eResponse 3: surface\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e98.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e98.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e98.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e60.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.67\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e99.57\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.67\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e96.21\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.96\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e98.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e2\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e60.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.03\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e98.05\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.68\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e90.5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.91\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e3.88\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e97.51\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e99.23\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e11\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e60.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.84\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e99.46\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.99\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e60.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e2.86\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e98.16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e5\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.67\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e95.15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.95\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e14\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.30\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e98.19\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e15\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e30.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.68\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e93.76\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.94\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e2.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e97.64\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.98\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e17\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e45.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e10.00\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e0.10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e0.67\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\"\u003e \u003cp\u003e94.21\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c8\"\u003e \u003cp\u003e0.94\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eFurther analysis of data was addressed in terms of ANOVA, mathematical model, and optimization. The ANOVA of Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e helped in identifying the model’s significance terms. The power of the variable was used to confirm the quadratic models. The models displayed the inhibition efficiency as a function of the factors. The interactive behavior of the factors was also identified.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab6\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 6\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eANOVA for the corrosion Inhibitor by NH.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSource model\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eSum of squares\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eDf\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMean square\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eF- value\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ep-value\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003eProb \u0026gt; F\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.47\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e9\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.61\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e498.69\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003eSignificant\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA- Temperature\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.91\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.91\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e282.56\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB- Inhibitor conc\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.85\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e4.85\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1504.38\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC- Medium conc.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e5.43\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e5.43\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e1683.26\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.11\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.11\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e35.01\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.0006\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.61\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.61\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e189.77\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC\u003csup\u003e2\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.37\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.37\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e114.58\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAB\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e107.94\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAC\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.35\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e107.94\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eBC\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.38\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e1.38\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e428.10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u0026lt; 0.0001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eResidual\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.023\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e7\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e3.225E-003\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eLack of Fit\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.023\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e3\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e7.525E-003\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePure Error\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e4\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eCor Total\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e14.50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e16\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e\u0026nbsp;\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eStd. Dev.\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.057\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eR-Squared\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.9984\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMean\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e1.41\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eAdj R-Squared\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.9964\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC.V. %\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e4.04\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003ePred R-Squared\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e0.9751\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePRESS\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.36\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colspan=\"3\" nameend=\"c6\" namest=\"c4\"\u003e \u003cp\u003eAdeq Precision\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c7\"\u003e \u003cp\u003e75.163\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eA mathematical model for the corrosion inhibition was given in Eq.\u0026nbsp;4.\u003c/p\u003e\n\u003ch3\u003eIE = + 98.19 + 2.45A (4)\u003c/h3\u003e\n\u003cp\u003eThe optimum parameters for corrosion inhibition of mild-steel as given in Table\u0026nbsp;\u003cspan refid=\"Tab7\" class=\"InternalRef\"\u003e7\u003c/span\u003e show values as concentration 10g/l, temperature 50\u003csup\u003e0\u003c/sup\u003eC, time 6hr and efficiency 99.13% for the mild-steel in acidic medium with NH as inhibitor.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab7\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 7\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eOptimum parameters of the NH Inhibitor.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMolar quantity\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eNH Quantity\u003c/p\u003e \u003cp\u003emg/L\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eTemp. \u003csup\u003eo\u003c/sup\u003e C\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eInhibition\u003c/p\u003e \u003cp\u003eefficiency (%)\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0.5M HCl\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e99.13\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eThis high value efficiency indicates that natural honey is a good corrosion controller of metal surfaces. This result was validated in Table\u0026nbsp;\u003cspan refid=\"Tab8\" class=\"InternalRef\"\u003e8\u003c/span\u003e by conducting additional experiments.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab8\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 8\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResult validation for the corrosion inhibitor NH.\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"6\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eMolar\u003c/p\u003e \u003cp\u003equantity\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNH quantity\u003c/p\u003e \u003cp\u003emg/L\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eTemperature\u003c/p\u003e \u003cp\u003e\u003csup\u003eo\u003c/sup\u003e C\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003ePred. efficiency (%).\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eMeasured efficiency (%).\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003ePercentage error (%).\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e0.5M HCl\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e10\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e50\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e99.13\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e \u003cp\u003e99.52\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c6\"\u003e \u003cp\u003e0.39\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003e3.15 Quantum Simulation (Computational) Studies Result\u003c/h2\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab9\" class=\"InternalRef\"\u003e9\u003c/span\u003e shows the calculated value of quantum chemical properties of NH, and Table\u0026nbsp;\u003cspan refid=\"Tab10\" class=\"InternalRef\"\u003e10\u003c/span\u003e shows calculated charges and indices for attacks by NH molecule. When the values of E\u003csub\u003eLUMO\u003c/sub\u003e were lesser, it signified a higher ability of electrons to accept molecule [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e–\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Similarly, low values of the energy gap, ΔE, gave good effectiveness of the inhibition as the energy reduction leads in terminating electrons. Calculated values of energies (of frontier molecular orbitals) were − 6.600 and − 6.512 e V. The High value of this energy shows NH’s ability to give out electrons at the surface of mild-steel. The ΔE-value of (0.088 eV) obtained shows the NHs’ high reactivity on the surface.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab9\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 9\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eValue of quantum chemical properties of (inhibitor) natural honey\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"2\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eProperty\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNatural honey eV\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE\u003csub\u003eHOMO\u003c/sub\u003e (e V)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-6.600\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE\u003csub\u003eLUMO\u003c/sub\u003e (e V)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-6.512\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eE\u003csub\u003eLUMO−HOMO\u003c/sub\u003e (e V)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.088\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eF\u003csup\u003e+\u003c/sup\u003e (Mulliken)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.289\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eF\u003csup\u003e−\u003c/sup\u003e (Mulliken)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.375\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAtomic charge\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.937\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab10\" class=\"InternalRef\"\u003e10\u003c/span\u003e shows the calculated value of quantum chemical properties of NH, and Table\u0026nbsp;\u003cspan refid=\"Tab11\" class=\"InternalRef\"\u003e11\u003c/span\u003e shows a calculated Mulliken atomic charges and Fukui indices for nucleophilic (F\u003csup\u003e+\u003c/sup\u003e) and electrophilic (F\u003csup\u003e-\u003c/sup\u003e) attacks by NH molecule.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab10\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 10\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMulliken atomic charges and Fukui indices for natural honey molecule\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"4\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAtom\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eAtomic Charge\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eF\u003csup\u003e+\u003c/sup\u003e (nucleophilic)\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eF\u003csup\u003e-\u003c/sup\u003e Electrophilic\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC (1)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.471\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.007\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC (2)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.078\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.003\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC (3)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.035\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.014\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC (4)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.058\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.006\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC (5)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.178\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eC (6)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.049\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.016\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO (7)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.458\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.037\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO (8)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1.193\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.296\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (9)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.445\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (10)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.390\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (11)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.545\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO (12)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.266\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.013\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO (13)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1.068\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.010\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (14)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.545\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.004\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (15)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.194\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO (16)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.273\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.084\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO (17)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-1.084\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.375\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (18)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.499\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.025\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (19)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e 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\u003cp\u003e0.613\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.001\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO (47)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.516\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (48)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.656\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (49)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.329\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (50)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.525\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eH (51)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e0.332\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.002\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eO (52)\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-0.202\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e0.005\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e \u003cp\u003e0.000\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003e3.16 Molecular Dynamics Simulation Results\u003c/h2\u003e \u003cp\u003eResults of binding (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{bind}\\)\u003c/span\u003e\u003c/span\u003e) and total (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{total}\\)\u003c/span\u003e\u003c/span\u003e) energies calculated with Eq.\u0026nbsp;\u003cspan refid=\"Equ2\" class=\"InternalRef\"\u003e5\u003c/span\u003e [\u003cspan additionalcitationids=\"CR38 CR39\" citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e–\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e] were arranged in Table\u0026nbsp;\u003cspan refid=\"Tab11\" class=\"InternalRef\"\u003e11\u003c/span\u003e:\u003c/p\u003e\u003cdiv id=\"Equ2\" class=\"Equation\"\u003e\u003cdiv format=\"TEX\" class=\"mathdisplay\" id=\"FileID_Equ2\" name=\"EquationSource\"\u003e\n$$\\:{E}_{bind}=\\:{E}_{total}-({E}_{inh}+\\:{E}_{metal})$$\u003c/div\u003e\u003cdiv class=\"EquationNumber\"\u003e5\u003c/div\u003e\u003c/div\u003e\u003cp\u003e\u003c/p\u003e \u003cp\u003eValues indicate that binding energy was negative, which implied an exothermic reaction. Increases in binding energy made adsorption easier and enhanced efficiency.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab11\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 11\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eMolecular dynamics simulation results of binding and total energies\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e\u003ccolgroup cols=\"3\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eEnergy\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{bind}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003e\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{total}\\)\u003c/span\u003e\u003c/span\u003e\u003c/p\u003e \u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eNatural honey quantity\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003e-171.82095\u003c/p\u003e \u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e-2146.517620.\u003c/p\u003e \u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e \u003cp\u003e\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003e3.17 SEM\u003c/h2\u003e \u003cp\u003eThe Analysis Result was shown in plate 2 (a to f). [SEM images for ‘a’ unexposed mild steel in 0.5 M HCl; b, c, and d exposed mild steel in blank solution at (2, 4, 6,) g/L of NH respectively, and e and f exposed mild steel in 0.5 M HCl containing (8 and 10) g/L natural honey at 50°C for 6 h].\u003c/p\u003e \u003cp\u003eNow, image ‘2a’ is shown expanded as an example of the rest.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec14\" class=\"Section2\"\u003e \u003ch2\u003e3.2 DISCUSSION\u003c/h2\u003e \u003cp\u003eFTIR spectrum with peaks show absorbance on the vertical axis and frequency on the horizontal axis of the NH [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e–\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. Analysis of NH revealed the presence of C-H bend, =C-H bend, RCH-C’ R’’, C = O stretch, C = C-CH (R) OH, C-O stretch, Ro-O-H, N-H blend, R-C (O)-NH-R, C ≡ N stretch, carboxylic acids, C-H stretch of C = O aldehydes, O-H stretch carboxylic acid, N-H stretch amines-primary, hydrogen-bonded O-H stretch, carboxylic acids and N-H symmetric stretch amines.\u003c/p\u003e \u003cp\u003eCurves for the mild-steel samples in 0.5 M hydrochloric acid without and with natural honey exhibit active dissolution, as in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, that shifted E\u003csub\u003ecorr\u003c/sub\u003e in an anodic direction. This anodic polarization was more pronounced than the cathodic, indicating that corrosion was under anodic control at all NH concentrations. However, at high concentrations, NH abridged de-polarization effect and subsequently retards anodic dissolution and cathodic reactions. Its presence moved the \u003cem\u003eE\u003c/em\u003e\u003csub\u003e\u003cem\u003ecorr\u003c/em\u003e\u003c/sub\u003e towards pessimistic potential at high and low concentrations. This proved that NH hindered the discharging of hydrogen gas and the anodic dissolution of metal. While NH was added, it echoed the performance of inhibition potential [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]. Evaluating the \u003cem\u003eE\u003c/em\u003e\u003csub\u003e\u003cem\u003ecorr\u003c/em\u003e\u003c/sub\u003e value, the inhibitor was viewed as cathodic or anodic when displacement was greater than 85 mV. However, it became a mixed inhibitor when displacement was below 85 mV. Another proof was the NH’s reduction of current densities in cathodic and anodic regions.\u003c/p\u003e \u003cp\u003eThe test was performed at the open circuit potential (OCP). High frequency intercept with real axis in the plots was ascribed to solution resistance \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{R}}_{\\varvec{s}}\\)\u003c/span\u003e\u003c/span\u003e and low frequency to charge transfer resistance \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{R}}_{\\varvec{c}\\varvec{t}}\\)\u003c/span\u003e\u003c/span\u003e. The numerical values of impedance parameters are arranged in Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. Values of \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{\\varvec{C}}_{\\varvec{d}\\varvec{l}}\\)\u003c/span\u003e\u003c/span\u003e decreased [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e] due to a decrease in dielectric constant and/or an increase in double-layer thickness. Slight variations in values of corrosion rate and efficiency were ascribable to different techniques applied.\u003c/p\u003e \u003cp\u003eIncorporation of NH into mild-steel coupons dissolved in 0.5 M HCl at variable temperatures, controlled weight-loss as it increased temperatures. See Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e.\u003c/p\u003e \u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e shows the variation effects of different NH concentrations as inhibitors at different temperatures. The rate of corrosion decreased with temperature, and inhibition action increased, indicating a reduction in temperature. A stable corroded surface was formed and thereby prevented further diffusion of diluted acid.\u003c/p\u003e \u003cp\u003eObserved increment in concentration corresponds to increment in efficiency. Hence, maximum efficiency is 99.13% at 10 g/L and 50\u003csup\u003eo\u003c/sup\u003eC (see Table\u0026nbsp;\u003cspan refid=\"Tab4\" class=\"InternalRef\"\u003e4\u003c/span\u003e). Graphical analysis of the efficiency of honey on mild steel in acid was shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e. This study was observed to follow the Langmuir adsorption isotherm, and the observations were in agreement with previous studies by [\u003cspan citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e–\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e]. They applied the molecular simulation studies to optimize the adsorption structures of triazole derivatives and found that adsorption of the inhibitors on the mild steel surface in the acid solution obey the Langmuir isotherm.\u003c/p\u003e \u003cp\u003eFurther analysis of data was addressed in ANOVA, mathematical model, and optimization. From ANOVA, F- F-value of 498.69 implied significant model (Table\u0026nbsp;\u003cspan refid=\"Tab6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). There was only a 0.01 chance that a value this large could occur due to noise. Values of “Prob \u0026gt; F” \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\u0026lt;\\)\u003c/span\u003e\u003c/span\u003e 0.5000, and greater than 0.1000 indicated that model terms (A, B, C, A\u003csup\u003e2\u003c/sup\u003e, AB, AC, BC) were significant. “Pred R-Square” of 0.9751 was in reasonable agreement with “Adj R-Squared” of 0.9964; the difference being less than 0.2. “Adequate Precision” measures produced a ratio of 75.163, indicating adequate signal for this model to navigate the design space.\u003c/p\u003e \u003cp\u003eQuantum chemical calculations based on the density functional theory DFT method were performed on NH used as corrosion inhibitor for mild-steel in HCl-acid media to determine the relationship between the molecular structure of NH and inhibition efficiency. This method was an acceptable tool to assess the inhibitive performance of different materials. It was used as a channel to tackle experimental work on corrosion by [\u003cspan citationid=\"CR36\" class=\"CitationRef\"\u003e36\u003c/span\u003e–\u003cspan citationid=\"CR37\" class=\"CitationRef\"\u003e37\u003c/span\u003e]. The structural parameters, such as the frontier molecular orbital energy \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{HOMO}\\)\u003c/span\u003e\u003c/span\u003e (highest occupied molecular orbital), \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{LUMO}\\)\u003c/span\u003e\u003c/span\u003e (lowest unoccupied molecular orbital) and energy gap (ΔE = \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{LUMO}\\)\u003c/span\u003e\u003c/span\u003e – \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:{E}_{HOMO}\\)\u003c/span\u003e\u003c/span\u003e) were examined [\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e]. The charge distribution of the studied inhibitor, the absolute electronegativity (χ) values, and the fraction of electrons (ΔN) transferred from inhibitor to mild steel were also calculated and correlated with the inhibition efficiency. The movement of electrons led to the adsorption process, following the theory of chemical reactivity. Large vales of E\u003csub\u003eHOMO\u003c/sub\u003e show a huge aptitude of molecule to donate electrons to ease adsorption process, thus, specifying better performance of inhibitor. At lesser values of E\u003csub\u003eLUMO\u003c/sub\u003e, a higher ability of electrons to accept molecule was implied [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e–\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Similarly, low energy gap, ΔE of 0.088 eV indicates that NH had high adsorption reactivity on the surface of mild-steel. Thus, ΔE agreed with the result obtained elsewhere [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAdsorption sites were activated when NH electron structure and molecular orbit were assessed. DFT and electronic structure programs DMol\u003csup\u003e3\u003c/sup\u003e were adopted for simulation, and Mulliken population analysis was used in analyzing it. Local reactivity regarding nucleophilic and electrophilic were examined with Fukui indices to review active regions as in plate 1.\u003c/p\u003e \u003cp\u003eDifferences in the morphology of metals’ surface were presented in plate 2 (a-f). Electron micrographs revealed a strongly damaged surface owing to corrosion, and was reduced in the presence of inhibitor. These micrographs have close correlations with results earlier obtained in previous studies by [\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e–\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e "},{"header":"4.0 CONCLUSION","content":"\u003cp\u003eThe correlation between the quantum chemical parameters and inhibition efficiency of NH was investigated using density functional theory DFT calculation. The inhibition efficiency of the inhibitor is closely related to the quantum chemical parameters, E\u003csub\u003eHOMO\u003c/sub\u003e, E\u003csub\u003eLUMO\u003c/sub\u003e, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:\\varDelta\\:\\)\u003c/span\u003e\u003c/span\u003eE (energy-gap). The inhibitor has a considerable tendency for the protonation, the process which is a downhill exothermic reaction. The value of adsorption energy E\u003csub\u003eads\u003c/sub\u003e, is negative, which means that the adsorption could occur spontaneously. NH had the highest inhibition efficiency because it had the highest E\u003csub\u003eHOMO\u003c/sub\u003e energy value, and it was most capable of offering electrons. Molecular dynamic simulations were performed to study the adsorption behavior of the inhibitor on the mild-steel surface, and it was observed that the adsorption occurs mostly through the lone pair of electrons of the hetero-atoms and p-electrons of the NH. This study displays a good correlation between the theoretical and experimental data, which confirms the reliability of the quantum chemical methods to study the inhibition of corrosion of mild-steel surface. The anodic polarization was more pronounced than the cathodic, indicating that corrosion was under anodic control at all NH concentrations. The reduction of current densities, polarization measurement, and evaluation of \u003cem\u003eE\u003c/em\u003e\u003csub\u003e\u003cem\u003ecorr\u003c/em\u003e\u003c/sub\u003e value show NH as a good corrosion controller. The percentage efficiency of NH increased with the concentration and temperature. The highest, 99.13%, was obtained at a concentration of 10 mg/L with a temperature of 50 C. This study was observed to follow the Langmuir adsorption isotherm. Therefore, NA was a good corrosion inhibitor of mild steel in 0.5 M HCl surroundings.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor Contributions:\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEzeamaku Uche Luvia: Writing-Review and Editing, Investigation, Visualization, Formal Analysis, Software.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eOnyechere Chigozie: Writing-original draft, Data curation, Conceptualization.\u003cem\u003e\u0026nbsp;\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003eOkechukwu Dominic Onukwuli: Supervision, Project administration, Methodology.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003eObibuenyi, Ifeanyi John: Writing-Review and Editing, Investigation, Validation, \u0026nbsp;\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003e\u003cstrong\u003eDeclaration of Competing Interest:\u0026nbsp;\u003c/strong\u003e\u003c/li\u003e\n \u003cli\u003eThe authors declare that they have no known competing financial interests or personal relationships that could have influenced the work in this study.\u003c/li\u003e\n \u003cli\u003e\u003cstrong\u003eFunding Statement:\u003c/strong\u003e\u003c/li\u003e\n \u003cli\u003eAll authors certify that they have no affiliations with or involvement in any organization or entity with any financial interest or non-financial interest in the subject matter or materials discussed in this manuscript.\u0026nbsp;\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eDeclaration of Ethical Statement:\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research received ethical approval and complied with the guidelines and regulations of the studies. Informed consent was obtained from all participants. There were no human participants involved in the study. \u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cul\u003e\n \u003cli\u003eTherefore, research has been conducted with the highest standards for rigor and integrity.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eThe article study is original.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eThis work has not been submitted elsewhere and is not under consideration for publication elsewhere.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eThe work does not include libelous, defamatory, or unlawful statements.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eThere was no third-party material(s) included.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eProof of consent has been obtained for any named individuals or organizations.\u0026nbsp;\u003c/li\u003e\n \u003cli\u003eAuthorship has been agreed upon before submission, and no one has been gifted authorship or denied credit as an author (ghost authorship).\u0026nbsp;\u003c/li\u003e\n\u003c/ul\u003e\n\u003cp\u003e\u003cstrong\u003eData Availability:\u003c/strong\u003e No data was used in this article. However, the data that support the findings of this study are available from the corresponding author, [I. J. O], upon reasonable request.\u0026nbsp;\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFontana, M. G. \u003cem\u003eCorrosion engineering (third ed.).\u003c/em\u003e (Tara McGraw-Hill Publishing Company Limited, 2007).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eLandolt, D. \u003cem\u003eCorrosion and surface chemistry of metals\u003c/em\u003e (EPFL, 2009).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eCecchetto, L. et al. On the mechanism of the anodic protection of aluminum alloy AA5182 by emeraldine base coatings evidences of galvanic coupling. Electrochemical \u003cem\u003eActa, 52, 3485\u0026ndash;3492.\u003c/em\u003e (2007).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eKim, D. K. et al. Electrochemical studies on the alternating current corrosion of mild steel under cathodic protection conditions in marine environments. \u003cem\u003eElectrochem. Acta\u003c/em\u003e. \u003cb\u003e51\u003c/b\u003e, 5259\u0026ndash;5267 (2006).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003ePraveen, B. M. et al. Corrosion studies of carbon nanotubes \u0026ndash; Zn composite coating. \u003cem\u003eSurface and Coatings Technology\u003c/em\u003e, 201, 5836\u0026ndash;5842. (2007).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAkpan, I. A. \u0026amp; Offiong, N. O. Effect of ethanolamine and ethylamine on the entropy content of the corrosion of mild steel in tetra-oxo-sulphate (VI) acid solution. \u003cem\u003eChemistry and Materials Research\u003c/em\u003e, 2(7), 40\u0026ndash;47. (2012).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eArthur, D. A. et al. 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C. et al. \u003cem\u003eResponse Surface methodology and experimental evaluation of the inhibitory properties of corn leaf extract for aluminum corrosion in acid media\u003c/em\u003e (Ani-Corrosion Methods and Materials, 2024).\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eY\u0026uuml;ce, A. O. Corrosion Inhibition Behavior of \u003cem\u003eRobinia pseudo-acacia\u003c/em\u003e Leaves Extract as an Eco-Friendly Inhibitor on Mild Steel in Acidic Media. \u003cem\u003eMet. Mater. Int.\u003c/em\u003e \u003cb\u003e26\u003c/b\u003e, 456\u0026ndash;466. \u003cspan class=\"ExternalRef\"\u003e\u003cspan class=\"RefSource\"\u003ehttps://doi.org/10.1007/s12540-019-00509-7\u003c/span\u003e\u003cspan address=\"10.1007/s12540-019-00509-7\" targettype=\"DOI\" class=\"RefTarget\"\u003e\u003c/span\u003e\u003c/span\u003e (2020).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"},{"header":"Plates","content":"\u003cp\u003ePlates 1 and 2 are available in the Supplementary Files section.\u003c/p\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Corrosion, inhibition, natural honey, mild steel, HCl, efficiency","lastPublishedDoi":"10.21203/rs.3.rs-5727302/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5727302/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis research investigates the role of natural honey (NH) as a corrosion inhibitor for mild steel in hydrochloric acid. The materials used include mild steel, hydrochloric acid, a Fourier transform infrared spectrophotometer, and a scanning electron microscope. Experimental treatments were performed using gravimetric, polarization, and impedance methods. FTIR analysis revealed the functional groups present in the honey, and the polarization measurement reached a steady state at a potential range of approximately 250 mV after 30 minutes of immersion at a scan rate of 0.33 mV/s. The results also show that NH inhibited cathodic and anodic reaction processes when the displacement was greater than 85 mV and a mixed-type inhibitor when the displacement was less than 85 mV. The weight losses were recorded as the average value of the difference between the initial and final weights of the three determinant coupons at a given time. The efficiency was validated, and the 99.52% obtained was close to the predicted value of 99.13%. The negative value of binding energy implied an exothermic reaction. The molecular dynamic simulation with a high energy gap indicates that NH had a high reactivity of adsorption and could be a mixed-type inhibitor. For these reasons, NH was adjudged a mixed-type inhibitor and a good quality corrosion controller of metal surfaces.\u003c/p\u003e","manuscriptTitle":"The Role of Natural Honey as a Corrosion Inhibitor for Mild Steel in Hydrochloric Acid","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-05-06 09:31:28","doi":"10.21203/rs.3.rs-5727302/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"reviewersInvited","content":"","date":"2025-04-30T08:37:12+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-18T16:52:44+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2025-04-04T10:33:43+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"b684fc12-f090-4d09-a43a-4ac562352c86","owner":[],"postedDate":"May 6th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":47895721,"name":"Physical sciences/Chemistry"},{"id":47895722,"name":"Physical sciences/Engineering"}],"tags":[],"updatedAt":"2025-06-16T07:23:43+00:00","versionOfRecord":[],"versionCreatedAt":"2025-05-06 09:31:28","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-5727302","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-5727302","identity":"rs-5727302","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}