Using the new Picker flow calorimeter, the excess heat capacity (C(,p)('E)) has been measured for systems containing normal, branched and cyclic alkanes. The results indicate two unusual effects: (1) a large negative contribution due to the destruction of orientational order in a pure n-alkane component, and (2) a positive contribution attributed to the "condensation" of a more freely-moving molecule or segment on a sterically-hindered branched alkane, resulting in a restriction of rotational movement, i.e. creation of order in the solution. Mixtures of cycloalkanes and their methyl derivatives also show unexpected positive effects in the excess heat capacity. Thus the plate-like cyclopentane molecule gives positive C(,p)('E) values when mixed with other plate-like methyl derivatives of cyclohexane suggesting a hindering of its molecular rotation. / Cyclohexane mixed with globular branched and cyclic alkanes shows S-shaped C(,p)('E) curves, negative at low concentration of cyclohexane but positive at high, indicating the possibility of a restriction of cyclohexane motion. / Effects of order are also apparent in the equation of state of a liquid. The thermal pressure coefficient for systems containing n-hexadecane has been found to be anomalous and is explained by a lowering of the internal energy of n-hexadecane by orientational order. / Excess volume (V('E)) has been studied for systems of branched and normal alkanes by investigating different effects contributing to the total V('E), particularly an important effect of a difference in thermal pressure coefficients of the two components.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.71829 |
| Date | January 1982 |
| Creators | Tra, Van-Huu. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Doctor of Philosophy (Department of Chemistry.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 000187027, proquestno: AAINK64520, Theses scanned by UMI/ProQuest. |
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