VAPOUR PRESSURES AND BOILING POINTS OF BINARY MIXTURES OF HYDROGEN PEROXIDE AND WATER

Abstract

The total vapour pressures of binary mixtures of hydrogen peroxide and water have been measured by means of the static method at 30, 45, and 60 °C. over the entire range of concentration. The vapour-pressure–composition curves have been found to exhibit large negative deviations from Raoult's law, but no minimum. A special apparatus and experimental technique were devised that enabled the composition of the vapour to be determined in each case. These data were used to obtain the partial pressures of both components. The values thus found are in good agreement with those calculated from the total vapour pressures by means of the Duhem Margules equation. The activities of water and hydrogen peroxide in their solutions have been calculated and interpreted on the basis of the polarity of the two pure liquids.The normal boiling point and latent heat of vaporization of the solutions were obtained by extrapolation of the vapour pressure data. The results are important in connection with the distillation of aqueous solutions of hydrogen peroxide.