SOME EFFECTS OF WATER-VAPOR ABSORPTION ON SODIUM CHLORIDES AT 25C

Abstract

The surface of sodium-chloride microcrystals has been ?strained? in an electrodeless high-frequency discharge. Surface areas of the blue product obtained in this way, after exposure to water vapor at 25C and unit relative vapor pressure, were plotted against time and the rates compared with the sintering rate of a normal surface. Induction periods were found in both cases indicating surface adsorption, during which time the surface does not change appreciably. The rates of sintering were found to differ considerably indicating that sintering of the ?blue? surface is much slower than that of the ?white? one. Both phenomena were found to follow first-order kinetics with respect to surface. The possible role of activated NaCl in ice nucleation and water coalescence in the atmosphere is discussed.