Equilibrium of three liquid phases and approach to the tricritical point in benzene-ethanol-water-ammonium sulfate mixtures

J.C. Lang and B. Widom

Physica A: Statistical Mechanics and its Applications, 1975, vol. 81, issue 2, 190-213

Abstract: We have determined the region of coexistence of three liquid phases in the system C6H6-EtOH-H2O-(NH4)2SO4 at 21°, 45°, 48° and 48.6°C, and have located the tricritical point. The temperature and composition at the tricritical point are Tt = 48.9°C and mass fractions xsalt = 0.0175, xwater = 0.351, xethanol = 0.450, xbenzene = 0.181. This composition is inferred to lie outside the three-phase region at 21° and 45°, in agreement with the phenomenological theory of Griffiths. The locus of the three liquid phases in the isothermal composition tetrahedron has the parabolic, inflected (cubic), and cusped aspects predicted by the theory. For the three exponents β1, β2, and β3 associated with the vanishing of the three characteristic dimensions of the coexistence region, we find β1 = 0.4, β2 = 1.0, β3 = 1.5, compared to the theoretical β1 = 12, β2 = 1, β3 = 32. We verify that the algebraic degree 1/β′ of the coexistence curve near the two critical end points exceeds its classical value of 2.

Date: 1975
References: View complete reference list from CitEc
Citations: View citations in EconPapers (1)

Downloads: (external link)
http://www.sciencedirect.com/science/article/pii/0378437175900631
Full text for ScienceDirect subscribers only. Journal offers the option of making the article available online on Science direct for a fee of $3,000

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:eee:phsmap:v:81:y:1975:i:2:p:190-213

DOI: 10.1016/0378-4371(75)90063-1

Access Statistics for this article

Physica A: Statistical Mechanics and its Applications is currently edited by K. A. Dawson, J. O. Indekeu, H.E. Stanley and C. Tsallis

More articles in Physica A: Statistical Mechanics and its Applications from Elsevier
Bibliographic data for series maintained by Catherine Liu ().