SURFACE-TENSION AND DENSITY OF THE SILVER CHLORIDE-RUBIDIUM CHLORIDE (AGCL RBCL) LIQUID SOLUTION

The surface tension and density of liquid silver chloride-rubidium chl oride melts were measured using maximum bubble pressure method. The ex periments were performed at the temperature interval of about 300 K, u sually starting from temperatures higher than 30 K in relation to the liquidus of the AgCl-RbCl phase diagram. Measurements were carried out for pure RbCl and for 9 liquid salt mixtures having the following mol e fractions of RbCl: 0.95, 0.9, 0.85, 0.8, 0.775, 0.7, 0.575, 0.45, 0. 3, 0.1, 0.03. The linear dependences of the surface tension and the de nsity were detected for all the investigated molten salts, and describ ed by the linear equations of the type: Y = a + bT, for which the a an d b parameters were calculated using the least-squares method. The obt ained surface tension and density isotherms at 1000 K and 1300 K clear y indicate the negative deviations from additivity. The temperature-co ncentration relation for the surface tension and density were worked o ut by the minimalization method of the aim function (sum of the 2nd po wer of difference between the measured and the calculated values). Iso therms of the molar volumes at 1000 K and 1300 K were calculated and t hey have shown a nearly linear dependence upon the concentration, espe cially for the solutions with molar fraction of the rubidium chloride lower than 0.5.