Critical behavior of binary mixture of { x C 6H 5CN + (1 − x) CH 3(CH 2) 12CH 3}: Measurements of coexistence curves, turbidity, and heat capacity

Abstract

(Liquid + liquid) coexistence curve, turbidity, and isobaric heat capacity per unit volume for the critical solution of {benzonitrile + n-tetradecane} have been measured. The critical exponents β, ν, γ, and α and system-dependent critical amplitudes B, ξ 0, χ 0, and A ±, corresponding to the difference of the general density variable of two coexisting phases Δ ρ, the correlation length ξ, the osmotic compressibility χ, and the isobaric heat capacity per unit volume C pV −1, have been deduced and were used to test some universal ratios. The behavior of the diameter of the coexistence curves showed good agreement with the complete scaling theory. The analysis of effective critical exponent β eff, which was well described by the crossover model proposed by Anisimov and Sengers, and effective critical exponent α eff indicated monotonic crossover phenomena from 3D-Ising behavior to mean-field one as the temperature departed from the critical point.