Dissociation Energies of Group VIa Gaseous Homonuclear Diatomic Molecules. I. Sulfur

A simultaneous Knudsen-torsion effusion experiment has been performed to establish equilibrium constants for the equilibrium S2(g)⇌2S(g). The gas was supplied from elemental sulfur vaporized from one-half of an alumina double oven to the other half from which effusion took place. Thrid-law values for the dissociation energy of S2(g) average to 101.7 ± 2.9 kcal/mole. As a test of the method, the dissociation energy of I2(g) was determined as 36.17 ± 0.77 kcal/mole in comparison with an accepted value of 35.538 kcal/mole.