KINETICS OF THE HYDRATION OF SODIUM AND POTASSIUM TRIPOLYPHOSPHATES.

The kinetic peculiarities of the hydration of Na//5P//3O//1//0 (I), Na//5P//3O//1//0 (II), K//5P//3O//1//0, and Na//yK//5// minus //yP//3O//1//0 (y equals 2, y equals 3), and commercial-grade sodium tripolyphosphate, established and compared at 20 degree C and humidities r equals 20-100%, showed that, in contrast to the other salts, Na//5P//3O//1//0 (II) and Na//3K//2P//3O//1//0 in the case of a rather high phase purity have the ability to absorb water vapor at a rate that increases with time. An activity-inversion effect, which consists in the fact that after the absorption of a certain amount of moisture, inactive Na//5P//3O//1//0 (II) and Na//3K//2P//3O//1//0 salts react rapidly with water vapor and less time is required for completion of their hydration than for active Na//5P//3O//1//0 (I) and Na//2K//3P//3O//1//0 salts, is characteristic for the Na//5P//3O//1//0 (I) and Na//5P//3O//1//0 (II) and Na//2K//3P//3O//1//0 and Na//3K//2P//30// 1//0 pairs.