The relation of the parameters of the critical point of liquid-gas transition with the Boyle temperature

Abstract

It is shown that the ratio of the Boyle temperature to the product of critical temperature and critical compressibility factor is equal to the number 9 with high accuracy for 21 real substances as predicted from Van-der-Waals equation of state. The relation is suggested to find the critical volume via the ratio of the Boyle temperature to the critical pressure. The formula is suggested also to define the critical volume via the critical temperature and the parameters of the linear line of unite compressibility.