The <i>P</i> <i>V</i> <i>T</i> properties of nitrogen from −20 to +35 °C and 200 to 570 MPa, and some comparisons with argon and the Lennard-Jones (6-12) fluid

Abstract

The density ρ(T, p) of nitrogen has been measured for T=−20 to +35 °C and p in the range 200 to 570 MPa, using a method already described in a paper which included results for argon. An improvement in the accuracy with which the quantities of gas are measured has reduced the overall uncertainty in ρ(T, p) to 0.03% at the 95% confidence level. The results are presented graphically and in the form of a fitted equation, and are compared with those of other workers. A comparison is made with the results of the argon study and a hypothetical Lennard-Jones fluid, in terms of the density, the internal energy and the entropy, and the internal kinetic energy of the molecules as calculated by Schottky’s method.