DISSOCIATION ENERGIES OF GROUP 6A GASEOUS HOMONUCLEAR DIATOMIC MOLECULES .2. SELENIUM

The dissociation energy of Se2(g) has been determined by the simultaneous Knudsen-torsion effusion method. The equilibrium, Se 2(g)⇋2Se(g), has been studied with a double-oven, alumina effusion cell; one oven contained elemental selenium and supplied vapor to the hot oven from which the effusion occurred. The value of D0° found in this study is 75.7±2.5 kcal/mole; this value is in excellent agreement with values determined in mass-spectrometric equilibrium studies and in good agreement with a value from a spectroscopic experiment.