Organic Bond Strengths and the Heat of Vaporization of Carbon

Abstract

KINETIC studies on several independent chemical reactions have led to a value of about 104 kcal. for the heat X of removal of the first hydrogen from methane. Thus Trenner, Morikawa and H. S. Taylor1obtained 108 ± 5 kcal. from the reaction of deuterium atoms with methane, Patat2 a value of about 103 kcal. from the ortho-para hydrogen conversion by methyl radicals, and Rice and Dooley3 a value 100 ± 6 kcal. from the thermal decomposition of methane at high temperatures. Butler and Polanyi4 have measured the velocity of the homogeneous thermal decomposition of alkyl iodides at low pressures, and their results, together with some thermo-chemical data, lead to the value X = 103.65.