Abstract
The properties of fluid argon are investigated via the maxima and minima along isotherms of selected thermodynamic functions, the isothermal compressibility, χT, the constant volume specific heat, CV, and the speed of sound, W. Calculations are based on an equation of state due to Gosman, McCarty, and Hust and on speed of sound data compiled by Thoen, Vangeel, and Van Dael. The calculation of CV in the dense liquid region, from the equation of state and from the speed of sound, is discussed in detail. Also, the linear dependence of W on the density in the liquid region is reconciled with the behaviour of W at temperatures above critical to obtain a unified description of the variation of W along isotherms.