DISTRIBUTION constants for krypton in the vapour-liquid system krypton-oxygen are not known precisely1, 2 and no figures have been reported for the industrially important infinitely dilute solutions. Vapour-liquid equilibrium measurements were carried out by the author over the temperature range 93-57-106-52 ยฐ K with particular attention to very low concentrations of krypton in liquid oxygen.
Equilibrium data were obtained for concentrations of krypton ranging from 0-01 mole per cent (100 p.p.m.) to 10 mole per cent at 93.57 ยฐ K, and for 0.05 and 0-10 mole per cent krypton at 101.35 ยฐ K and 106.52 ยฐ K. The highest concentration used, of l0 mole per cent, is well below the solubility limit of solid krypton (t.p. = 115.77 ยฐ K) in liquid oxygen. Concentrations of krypton less than 0-10 mole per cent were found to be sufficiently low to establish the value of the distribution constant for the infinitely dilute solution. Measurements at concentrations of krypton up to 10 mole per cent were carried out in order to aid in estimating the reliability of the data for the very dilute solutions of krypton. A correlation of the data showed a systematic error in the data at 1.0 mole per cent of krypton which was traced to the analyses. These data, with a mean error of 3"3 per cent of the activity coefficient value, were not used in computing the constants for the final correlating function.