The Isotope Effect of Electromigration in Some Solid Alkali Halides

The isotope effect of electromigration in some solid alkali halides was determined in their intrinsic ionic conductivity region. The external cationic mass effect (i. e., relative difference in cationic mobility/relative difference in mass) of lithium fluoride, chloride, bromide and iodide and potassium chloride was -0.243, -0.207, -0.195, -0.190 and -0.254, respectively, at 750, 540, 470, 370 and 600 °C, respectively. No difference of the mass effect was found between polycrystalline and single crystal potassium chloride. When the available data for the mass effect of the solid salts are plotted against the activation energy for electric conductance, there is a tendency for the mass effect to increase as the activation energy increases.

Catalysis of the slow combustion of acetaldehyde by alkali halides

Solid alkali halides catalyse the slow combustion of acetaldehyde vapour at 100-125�. The catalysis (by chlorides) is not sensitive to the nature of the cation (Li+, K+, Cs+, Ca2+, Ba2+) but changes drastically with a change in anion, the relative catalytic effects being in the order Br-�Cl- > F-. I- probably exerts an inhibitory effect. The catalysis is attributed tentatively to the sensitizing action of free halogen produced by reaction of acetyl hydroperoxide with the halide. There is a general kinetic similarity with the much weaker catalysis by glass observed by previous workers.