A calorimetric enthalpy of dilution technique was applied to the investigation of carboxylic acid self-association in organic solvents at 25°C. Data were analyzed in terms of the apparent relative molar enthalpy, Φ_L, and were found to fit adequately a monomer-dimer model. Values of the thermodynamic dimerization parameters K_2 and ΔH°_2 were obtained for several methyl-, halo-, and phenyl-substituted acetic and propionic acids in benzene. Some of the acids were also studied in toluene and carbon tetrachloride. Substituent effects on K_2 and ΔH°_2 were in general small and were explained adequately by an electrostatic model of the monomer-dimer interaction. Solvent effects were explained by considering an acid-solvent interaction. The effect on the results of small amounts of water in the solvent was found to be a function of aqueous acid strength. Acetic acid and other weak acids were unaffected by water in the solvent, but a significant affect was observed with stronger acids, such as the haloacetic acids.
| Identifer | oai:union.ndltd.org:BGMYU2/oai:scholarsarchive.byu.edu:etd-9505 |
| Date | 01 August 1975 |
| Creators | Zaugg, Noel S. |
| Publisher | BYU ScholarsArchive |
| Source Sets | Brigham Young University |
| Detected Language | English |
| Type | text |
| Source | Theses and Dissertations |
| Rights | http://lib.byu.edu/about/copyright/ |
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