BREAKDOWN OF THE RULE OF LINEARITY OF WATER ISOACTIVITY LINES IN A SYSTEM CONTAINING SOLID SOLUTIONS

摘要

Osmotic coefficients of water have been measured isopiestically for the entire region of homogeneous ternary solutions for the Rb2SO4- (NH4)(2)SO4- H2O system at 25 degrees C. One might expect that water isoactivity lines should be straight since this system involves a continuous series of solid solutions. The related systems (K2SO4 - Rb2SO4 - H2O and K2SO4-(NH4)(2)SO4 - H2O) obey the ''linearity of water isoactivity lines'' rule. Contrary to expectations, the Rb2SO4-(NH4)(2)SO4-H2O appears to be the first water-salt system containing continuous solid solutions in which the mentioned rule is not obeyed. [References: 15]