PHOTOCHEMICAL DECOMPOSITION OF AN AQUEOUS-SOLUTION OF SODIUM SULFIDE

Photolysis of an aqueous (pH almost-equal-to 11) solution of sodium su lphide was studied on exposure to UV irradiation at lambda = 248 nm. H -2 and sulphane (H2S2) are the primary molecular products resulting fr om H atom interaction with HS- and recombination of two S.- anion radi cals respectively. The limiting quantum yield (approximately 0.04) is much lower than that of the gas phase photolysis or radiolysis of hydr ogen sulphide. The kinetic regulations observed are explained in terms of the Noyes model of scavenger competition with the cross-linked rec ombination of active intermediate species.