Catalysis by hydrogen halides in the gas phase. XVII. Isobutyric acid and hydrogen bromide

Abstract

Hydrogen bromide catalyses the decomposition of isobutyric acid into propene, carbon monoxide, and water at 369-454º. Hydrogen bromide is not lost. Individual runs follow the first-order rate law, and the rate constants are proportional to the hydrogen bromide pressure. The Arrhenius parameters are: E = 33.17 kcal mole^-1 and A = 10^12.87 sec^-1 ml mole^-1, and the reaction is homogeneous and molecular. Added water or methanol retards the reaction.