Reaction between hydrogen and potassium chloride crystals doped with nitrite and nitrate

The reaction has been studied between hydrogen gas and potassium chloride crystals, doped with nitrite and nitrate ions. Kinetics indicate that the reaction rate is governed by the diffusion of hydrogen molecules in the lattice. Mass spectrometric measurements, combined with earlier data, show that the reaction products are essentially nitrogen gas, water and hydroxyl ions. Reaction equations and a theoretical rate expression are proposed. The gaseous products agglomerate to form cubic cavities which, by their expansion, cause a density decrease of several percent in the crystals. The dependence of the activation energy on cavity concentration is discussed.