P‐V‐T and Bubble‐point Measurements in the System HBr – H2O and its Critical Behaviour

Abstract

Abstractp‐V‐T measurements on HBr/H2O mixtures up to 820 K and 1500 bar in the complete range between pure H2O and pure HBr are reported. The bubble‐point line has been determined by visual observation up to about 690 K and 500 bar. – For the vapour phase an equation of state (Dieterici‐type) with mixing rules is applied. The experimental data including literature values are analyzed by integration of the Gibbs‐Duhem equation. – The system HBr/H2O is azeotropic even at elevated pressures. The azeotropic line intersects the high temperature branch of the critical curve at about xHBr = 0.045, 684 K and 335 bar. The low temperature branch of the critical curve is nearly identical to the critical point of HBr.