Critical behavior of binary mixture of {x C6H5CN + (1 − x) CH3(CH2)12CH3}: Measurements of coexistence curves, turbidity, and heat capacity

(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, ξ0, χ0, and A±, corresponding to the difference of the general density variable of two coexisting phases Δρ, the correlation length ξ, the osmotic compressibility χ, and the isobaric heat capacity per unit volume CpV−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 βeff, which was well described by the crossover model proposed by Anisimov and Sengers, and effective critical exponent αeff indicated monotonic crossover phenomena from 3D-Ising behavior to mean-field one as the temperature departed from the critical point.

Research highlights► Coexistence curve, turbidity and heat capacity of critical solution were measured. ► Critical amplitudes were determined to test universal ratios. ► Complete scaling theory was verified. ► Monotonic critical crossover behavior was demonstrated.