Evolution of Water from Alkali Halide Single Crystals

Abstract
The evolution of water upon heating in vacuum of NaCl and KCl single crystals which were exposed to controlled humidities for definite time intervals has been studied. Three types of water evolution are observed: (I) a constantly increasing rate of H2O with increasing temperature attributed to bulk H2O impurity; (II) desorption peaks which are believed to be connected with a NaOH‐hydrate (KOH‐hydrate) formation; and (III) bursts which are characteristic of crystals exposed to a saturated‐solution vapor pressure.