On Molecule Symmetry, Latent Heat, and Entropy

On Molecule Symmetry, Latent Heat, and Entropy | 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Share Download PDF Research Article On Molecule Symmetry, Latent Heat, and Entropy Henmei Ni This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8975789/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract This paper suggested correlating entropy with the geometric symmetry of molecular orbitals rather than with the atomic mass distribution within a molecule. Employing the NIST thermodynamic parameters of substances at saturation, linear regressions of exothermic heat over T give \({{\epsilon}}_{exo}=B-\frac{3+2A}{2}RT\) . B is the molar heat of liquefication, which equals the latent heat ( \(\varDelta{H}_{v}^{\varPhi}\) ) at the boiling point. A reflects the molecule's symmetry; the more symmetric the molecular orbits, the smaller A . For example, the symmetry of inert gas atoms gives the operation number n = 1 in the theoretical frame of the geometric symmetry of atomic mass distribution. However, three p orbitals give n = 7; correspondingly, the A values for Ne, Ar, Kr, and Xe are 2.5518, 2.9104, 2.9140, and 2.9178. Similarly, a tetrahedral C sp 3 gives n = 8, CH 4 : A = 2.9519. Hence, assuming that \(\frac{3+2A}{2}R\) is the lost entropy, \(\frac{n-2A}{2}R\) may be regarded as the residual in liquid. According to the above suggestion, CO is more symmetric than CO 2 . Moreover, the similarity in A between ethylene and ethane, propylene and propane, etc., implies that the C-C π bond should be rotatable rather than rigid. Helium-4 superfluid finds an increase in entropy as T decreases from 3.5 to 0.8 K. Clausius-Clapeyron equation was derived from \({{\epsilon}}_{exo}\) . Thermodynamics and statistical mechanics Molecule Symmetry Latent Heat Heat Transfer Superfluid Phase Transition Thermodynamics Full Text Additional Declarations The authors declare no competing interests. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. 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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-8975789","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":597428125,"identity":"cd94d1bf-5c91-40c4-82c0-d52515a0ce9a","order_by":0,"name":"Henmei Ni","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA2ElEQVRIiWNgGAWjYBACAxjJxt4AZjI2EK+F5wBJWkBAIoFILebsvUc3fChgyOOTfP7wMQ+DjeyGA8zPHuDTYtlzLu3mDAOGYjbpHGNjHoY04w0H2MwN8GkxuJFjdpvHgCGxTTqHTZqH4XDihgM8bBJ4tdx/Y3b7D0iL5PHnv3kY/hOh5QaP2W0GkBYJBjNmHoYDRGg5k2N2swekhSfHWHKOQbLxzMNsZvi1HD9jduPHH4bE+e3HH354U2En23e8+RleLVDwH2YCEDMToX4UjIJRMApGAX4AAOIARTvJRFcoAAAAAElFTkSuQmCC","orcid":"https://orcid.org/0000-0002-3315-8475","institution":"School of Chemistry and Chemical Engineering, Southeast University","correspondingAuthor":true,"prefix":"","firstName":"Henmei","middleName":"","lastName":"Ni","suffix":""}],"badges":[],"createdAt":"2026-02-26 09:10:29","currentVersionCode":1,"declarations":{"humanSubjects":false,"vertebrateSubjects":false,"conflictsOfInterestStatement":false,"humanSubjectEthicalGuidelines":false,"humanSubjectConsent":false,"humanSubjectClinicalTrial":false,"humanSubjectCaseReport":false,"vertebrateSubjectEthicalGuidelines":false},"doi":"10.21203/rs.3.rs-8975789/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8975789/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104398177,"identity":"723fdbb3-7b00-455a-a920-e6f6946b2da0","added_by":"auto","created_at":"2026-03-11 12:00:16","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1309116,"visible":true,"origin":"","legend":"","description":"","filename":"SymmetryLatentHeat20260226.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8975789/v1_covered_4323d071-0a51-4e17-901d-8cf53ad68dd4.pdf"}],"financialInterests":"The authors declare no competing interests.","formattedTitle":"\u003cp\u003e\u003cstrong\u003eOn Molecule Symmetry, Latent Heat, and Entropy\u003c/strong\u003e\u003c/p\u003e","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"Southeast University","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Molecule Symmetry, Latent Heat, Heat Transfer, Superfluid, Phase Transition, Thermodynamics","lastPublishedDoi":"10.21203/rs.3.rs-8975789/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8975789/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eThis paper suggested correlating entropy with the geometric symmetry of molecular orbitals rather than with the atomic mass distribution within a molecule. Employing the NIST thermodynamic parameters of substances at saturation, linear regressions of exothermic heat over \u003cem\u003eT\u003c/em\u003e give \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({{\\epsilon}}_{exo}=B-\\frac{3+2A}{2}RT\\)\u003c/span\u003e\u003c/span\u003e. \u003cem\u003eB\u003c/em\u003e is the molar heat of liquefication, which equals the latent heat (\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\varDelta{H}_{v}^{\\varPhi}\\)\u003c/span\u003e\u003c/span\u003e) at the boiling point. \u003cem\u003eA\u003c/em\u003e reflects the molecule's symmetry; the more symmetric the molecular orbits, the smaller \u003cem\u003eA\u003c/em\u003e. For example, the symmetry of inert gas atoms gives the operation number \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;1 in the theoretical frame of the geometric symmetry of atomic mass distribution. However, three \u003cem\u003ep\u003c/em\u003e orbitals give \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;7; correspondingly, the \u003cem\u003eA\u003c/em\u003e values for Ne, Ar, Kr, and Xe are 2.5518, 2.9104, 2.9140, and 2.9178. Similarly, a tetrahedral C \u003cem\u003esp\u003c/em\u003e\u003csup\u003e3\u003c/sup\u003e gives \u003cem\u003en\u003c/em\u003e\u0026thinsp;=\u0026thinsp;8, CH\u003csub\u003e4\u003c/sub\u003e: \u003cem\u003eA\u003c/em\u003e\u0026thinsp;=\u0026thinsp;2.9519. Hence, assuming that \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{3+2A}{2}R\\)\u003c/span\u003e\u003c/span\u003e is the lost entropy, \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\frac{n-2A}{2}R\\)\u003c/span\u003e\u003c/span\u003e may be regarded as the residual in liquid. According to the above suggestion, CO is more symmetric than CO\u003csub\u003e2\u003c/sub\u003e. Moreover, the similarity in \u003cem\u003eA\u003c/em\u003e between ethylene and ethane, propylene and propane, etc., implies that the C-C π bond should be rotatable rather than rigid. Helium-4 superfluid finds an increase in entropy as \u003cem\u003eT\u003c/em\u003e decreases from 3.5 to 0.8 K. Clausius-Clapeyron equation was derived from \u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\({{\\epsilon}}_{exo}\\)\u003c/span\u003e\u003c/span\u003e.\u003c/p\u003e","manuscriptTitle":"On Molecule Symmetry, Latent Heat, and Entropy","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-02-27 02:42:24","doi":"10.21203/rs.3.rs-8975789/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"0029321c-3e15-45d3-be38-a3f5c1b957d5","owner":[],"postedDate":"February 27th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":63571562,"name":"Thermodynamics and statistical mechanics"}],"tags":[],"updatedAt":"2026-02-27T02:42:25+00:00","versionOfRecord":[],"versionCreatedAt":"2026-02-27 02:42:24","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8975789","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8975789","identity":"rs-8975789","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}