(Solid + liquid) phase equilibria in binary mixtures containing benzene, a cycloalkane, an n-alkane, or tetrachloromethane An equation for representing (solid + liquid) phase equilibria

Abstract

Complete (solid + liquid) phase diagrams are reported for the 10 mixtures: {(1− x) c-C m H 2 m + xC 6H 6}, m = 6, 7, 8; {(1− x)C m H 2 m+2 + xC 6H 6}, m = 8, 11, 12; {(1− x)C m H 2 m+2 + xc-C 6H 12}, m = 8, 12; and {(1− x)C m H 2 m+2 + xCCl 4}, m = 8, 12. All are simple eutectic systems except for {(1− x)C 8H 18 + xCCl 4}, which has a solid-phase transition present on the CCl 4 side of the diagram. The semi-empirical equation: X E =x(1−x) ∑ J=0 n a j(1−2x) J is proposed for summarizing the curves of melting temperature T against mole fraction x, where T ∗ is the melting temperature of the pure substance and x ∗ is the value of x at T ∗ . The coefficients a J are fitted by the method of least squares. The equation very successfully describes the above systems. It also works very well for more complicated systems including those containing congruently melting or incongruently melting solid addition compounds.