CORRELATION BETWEEN THE CRITICAL INDEX AND THE CRITICAL AMPLITUDE OF THE SATURATION LINE

Based on the analysis of the experimental information on the critical amplitude and the critical index β of the saturation line, the correlation dependence = (β, ω) is determined as a function of β and the acentric factor ω. The proposed correlation is tested using 20 substances. The maximum relative deviations δ, of the experimental values of the critical amplitude from those calculated by the correlation (β, ω) for all considered substances are found to be modulo not higher than 6%. The hypothesis on universality of the critical amplitude (with the accuracy up to the critical index β) is refuted. It is shown that the critical amplitude is an individual characteristic of a substance, influenced by the degree of non-sphericity of molecules (ω).