Thermodynamic properties of binary mixtures of benzene, cyclohexane and carbon tetrachloride

Abstract

Phase-diagrams of carbon tetrachloride + cyclohexane, benzene + cyclohexane and carbon tetrachloride + benzene have been obtained by the method of thermal analysis.Mixtures of carbon tetrachloride and cyclohexane show complete miscibility in the liquid phase with some evidence of partial miscibility in the solid phase. The phase-diagram for benzene + cyclohexane shows a eutectic. The equilibrium diagram of carbon tetrachloride 4-benzene indicates the formation of two compounds having the formulae C6H6. Cc14 and C6H6. 2cc14.The thermodynamic analysis of the equilibrium data for mixtures of carbon tetrachloride and cyclohexane indicates the system to be a regular one. v. and p which are related to interchange energies in the liquid and solid phase respectively, are found to depend on temperature in the following manner, loglo cc = 5.67 -0.01 114T;loglo j3 = 5.73 -0.01115T. It appears from the analysis that CI and j3 increase enormously as the freezing point is approached. Guggenheim's analysis of the vapour pressure data for the system yields a value of v. at 30°C of 65.5 cal/mole whereas according to present investigation this reaches 930 cal/mole at -30°C.The system benzene + cyclohexane is found to be far from regular, in agreement with Scatchard's finding based on the examination of the vapour-liquid equilibrium data. This is due to the wide difference in the size and the shape of the two molecules.Binary mixtures of carbon tetrachloride, benzene and cyclohexane are thermodynamically interesting. Scatchard 1 and co-workers have measured the vapour pressure of mixtures of carbon tetrachloride + benzene, carbon tetrachloride + cyclohexane and benzene + cyclohexane. Data referring to the first two mixtures have been used by Guggenheim 2 for testing the regular solution theory. In order to study the magnitude of interchange energies in the solid and liquid phases near the freezing point, it was thought desirable to make a detailed experimental study of the solid-liquid equilibria of these systems. EXPERIMENTALMATERIALS AND THEIR PURIFICATION CARBON TETRAcHLoRIDE.-Carbon tetrachloride (A.R.) was purified by fractional distillation using a Precise Fractionation Assembly, model A, Todd Scientific Company, Springfield, P.A. The ratio of the still head was adjusted to 25 : 1. The purity of carbon tetrachloride was tested by a freezing-point 3 determination.BENzENE.-Benzene (B.D.H.) was purified by shaking with about 15 % of its volume of conc. HzSO4 in a stoppered funnel until the acid layer was colourless and thiophene was absent. After each shaking lasting for a few minutes, the mixture was allowed to settle and the lower layer of the acid was drawn off. It was shaken twice with water to remove most of the acid and then twice with a 10 % solution of NazC03. Finally it

Molar Heat Capacity and Isothermal Compressibility of Binary Liquid Mixtures: Carbon Tetrachloride + Benzene, Carbon Tetrachloride + Cylohexane and Benzene + Cylohexane

“…not very different from that of CCI, + cyclohexane. However, there is ample evidence for the occurrence of "charge transfer" complex formation [72,731 in this system [28,[74][75][76][77][78]. In particular, the paper of McGlashan and coworkers [79] on complex formation of carbon tetrachloride with benzene and other aromatic hydrocarbons was instrumental in correlating various experimental results along this line.…”

Coupled optimization and evaluation of phase equilibria and thermodynamic properties of the benzene‐cyclohexane system

“…The phase diagram has been reported by a number of investigators (Atwood, 1958;Donald and Ridgway, 1958;Jackowski, 1974b;Kravchenko, 1951ab;Pestalozza, 1907, 1908;Ott and Goates, 1983;Rastogi and Nigam, 1959;Ridgway and Butler, 1967;Seto, 1928), obtained by thermal analysis. The most recent work (Ott and Goates, 1983) has been more carefully done than the others and was taken as comparison standard for this evaluation.…”

“…The phase diagram has been described (Ott and Goates, 1983; Rastogi and Nigam, 1959) as a simple eutectic system, with little or no solid solubility. Ott and Goates (1983) made thermal analysis measurements also in dilute solutions (xE < 0.05 and > 0.95) and observed eutectic halts at all compositions except for xE > 0.95, suggesting that a solid solution of up to 5 mol % of benzene in cyclohexane may exist.…”

Dimerization Constants from Acoustic Measurements: Solutions of Benzene, Cyclohexylamine and Aniline in Cyclohexane

“…The system cyclohexane + benzene has been investigated relatively often [ 67 ], but the interpretations are not unanimous. The heats of mixing for C 6 H 12 + C 6 H 6 and the vapor pressure of these solutions show that this system is far from regular [ 68 ], although the calculations of Milano et al imply only slight non-ideal behavior [ 56 ]. Non-ideality of this system was also stressed by Bottomley and Coopes based on the vapor pressure method [ 69 ].…”