1.10.33: Gibbs Energies- Liquid Mixtures- Typically Non-Aqueous Positive; TNAP
For this sub-group of binary aqueous liquid mixtures, \({\mathrm{G}_{\mathrm{m}}}^{\mathrm{E}}\) is positive. An example of such a mixture is ‘water + ethanenitrile’. The positive \({\mathrm{G}_{\mathrm{m}}}^{\mathrm{E}}\) reflects endothermic mixing across nearly all the mole fraction range. These mixtures have a tendency to be partially miscible with an Upper Critical Solution Temperature, UCST. For aqueous mixtures the composition at the UCST is often ‘water-rich’. For ethanenitrile + water, the UCST is \(272 \mathrm{~K}\). The positive \({\mathrm{G}_{\mathrm{m}}}^{\mathrm{E}}\) and endothermic mixing are attributed to disruption of water-water hydrogen bonding by added mathrm{MeCN}; cf. \(\mathrm{CCl}_{4} + \mathrm{~MeOH}\) [1,2].
Footnotes
[1] MeCN + water.
- \({\mathrm{G}_{\mathrm{m}}}^{\mathrm{E}}\); H. T. French, J.Chem.Thermodyn.,1987, 19 ,1155.
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\({\mathrm{H}_{\mathrm{m}}}^{\mathrm{E}}\);
- R. H. Stokes, J.Chem.Thermodyn.,1987, 19 ,977;
- K. W. Morcom and R. W. Smith, J. Chem. Thermodyn., 1969, 1 ,503.
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Volumes
- A. J. Easteal and L. A. Woolf, J.Chem.Thermodyn.,1988, 20 ,693,701.
- D. A. Armitage, M. J. Blandamer, M. J. Foster, N. J. Hidden, K. W. Morcom, M. C. R. Symons and M. J. Wootten, Trans. Faraday Soc.,1968, 64 ,1193.
- Sound Absorption M. J. Blandamer, M. J. Foster and D. Waddington, Trans. Faraday Soc.,1970, 66 ,1369.
- Miscibility; M. Hurth and D. Woermann, Ber. Bunsenges. Phys. Chem., 1987, 91 , 614.
- Excess thermodynamic properties; G. Douheret, C. Moreau and A. Viallard, Fluid Phase Equilib., 1986, 26 ,221
- Analysis of TD properties; M. J. Blandamer, N. J. Blundell, J. Burgess, H. J. Cowles and I. M. Horn, J. Chem. Soc. Faraday Trans.,1990, 86 ,277.
[2] Propylene Carbonate Miscibility; N. F. Catherall and A. G. Williamson, J. Chem. Eng. Data, 1971, 16 , 335.