scholarly journals Phase Equilibria in the Systems Acetone–Methanol, Acetone–Cyclohexane, Methanol–Cyclohexane, and Acetone–Methanol–Cyclohexane

1972 ◽  
Vol 50 (4) ◽  
pp. 479-489 ◽  
Author(s):  
A. N. Campbell ◽  
S. C. Anand

The vapor pressure and vapor composition of the methanol–cyclohexane system were investigated at temperatures ranging from 25 to 50°. The same properties of the binary systems: acetone–methanol and acetone–cyclohexane, as well as those of the ternary system: methanol–cyclohexane–acetone, were determined experimentally at 25°. The total pressures and compositions of the vapor for solutions lying close to the critical solution temperature of the binary system or close to the plait point of the ternary system are constant within the range of experimental accuracy. All these systems show azeotropic behavior. The methanol–cyclohexane system has an equimolar excess Gibbs free energy, GE, at 25° of 384.7 cal/mol, while the corresponding equimolar value of GE for the acetone–methanol system at 25° is 102.6 and for the acetone–cyclohexane system, at 25°, it is 274.5 cal/mol.

1972 ◽  
Vol 50 (8) ◽  
pp. 1109-1114 ◽  
Author(s):  
A. N. Campbell ◽  
S. C. Anand

The density, dielectric constant, change of volume on mixing, refractive index, surface tension, and viscosity of the methanol–cyclohexane system have been investigated experimentally at temperatures ranging from 25° to 50°. The same properties of the binary systems acetone–methanol and acetone–cyclohexane, as well as of the ternary system methanol–cyclohexane–acetone were determined experimentally at 25°. The critical region of the partially miscible system methanol–cyclohexane has been investigated by determining the above physical properties at temperatures above and below the critical solution temperature. A similar investigation of the ternary system has been made, isothermally at 25°, by investigating solutions lying in the neighborhood of the plait point.The surface tension or a derived function of it, viz. the molecular surface energy, does not show a horizontal portion of the isotherm in the methanol–cyclohexane system, but the ternary system does show such a constant surface tension, probably fortuitously, all along the tangential line. The viscosity exhibits anomaly.All the systems show azeotropic behavior. The methanol–cyclohexane and acetone–cyclohexane systems show marked deviations in molar polarization from linearity and this agrees with the thermodynamic data, which indicate larger than unity values for the activity coefficients of the components' behavior (1). The viscosity isotherms of all these systems give no indication of the formation of any stable compound.


2018 ◽  
Vol 40 (1) ◽  
pp. 97-110
Author(s):  
Md Kamrul Hossain ◽  
M Abdur Rahaman ◽  
Shamim Akhtar

The viscosities, η , of pure n-heptane, toluene, o-xylene, mesitylene, and some of their binary mixtures covering the whole composition range have been measured at 298.15K. Deviations in viscosity, ∆η , was calculated using experimental results. The concentration dependencies of η were correlated to polynomial expressions, whereas, ∆η were fitted to the Redlich–Kister equation. Moreover, the values of the excess Gibbs free energy of activation, ∆G#E, of these mixtures were determined. Viscosity measurements of the binary systems were correlated with Grunberg and Nissan the three-body and four-body McAllister expressions. In all systems, ∆η were found to be negative in the whole range of composition with a single lobe having minimum at 0.6 mple fraction of aromatic hydrocarbon. While dispersive forces are suggested to dominate in n-heptane + toluene, for the other two systems  ‘favourable geometric fitting’ overpowers them due to the increasing number of  – CH3 groups in the relevant aromatic hydrocarbons. The Chittagong Univ. J. Sci. 40 : 97-110, 2018


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