Hydrogen Fluoride: 1. Specific Heat, Steam Pressure and Density Up to 300 deg C and 300 at

摘要

Specific heat c/sub v/, pressure p and density rho of pure hydrogen fluoride were first measured at temperatures of up to 300 deg C and 300 at. pressure. For this purpose, a tight and corrosion proof high pressure calorimeter with a capacity of 0.5 liter and 120 cal/degree of heat capacity was designed. The contents were heated by an integral heating element. Details of the equipment and the measuring process will be described. The densities of the liquid and gaseous HF were between 0.96 and 0.04 g/cm exp 3 . The results for c/sub r/ (T, rho) and p (T, rho) have been tabulated. Noticeable are the high c/sub r/ values up to 2 cal/g degree, or the 40 cal mol degree for subcritical densities. The isotherms of the specific heat between 190 and 259 deg C between 190 and 250 deg C show definite maximum values between rho = 0.04 and rho = 0.2 g/cm exp 3 . The measurements showed also the pressures and the equilibrium densities and steam and liquid. The critical HF data at f/sub kr/ = 3 deg C, P/sub kr/ = 66.2 +- 3.5 kg/cm exp 2 and rho/sub kr/ = 0.29 +- 0.03 g/cm exp 3 . The vaporization rate increases from 89.5 cal/g at 19.4 deg C to a maximum of 146 cal/g at 130 deg C, shows still 101 cal/g at 170 exp 0 C and then drops rapidly. 17 refs., 10 figs., 3 tabs. (ERA citation 11:024387)