The measurements of coexistence curves and turbidity for {xC(6)H(5)NO(2)+(1-x)CH3(CH2)(11)CH3} in the critical region

The coexistence curves and the turbidity of (nitrobenzene + tridecane) have been measured, and the critical amplitudes and exponents relating to the d ifference in density variables of two coexisting phases, the correlation le ngth, and the osmotic compressibility have been calculated. The values of e xponents are consistent with the theoretical predictions. The experimental results of the coexistence curves have also been analysed to examine Wegner correction terms and the behaviour of the diameter of the coexistence curv es. A combination of the Wegner equation and the expression for the diamete r have been used to successfully describe the coexistence curves. The molar mass dependence of the critical amplitudes of the correlation length and t he osmotic compressibility has been discussed. (C) 1999 Academic Press.