A laser flash photolysis study of nitrous acid in the aqueous phase

Abstract

The OH quantum yield from the photolysis of nitrous acid in the aqueous phase by the 355 nm light was measured to be 0.25 ± 0.03. OH radical thus formed reacted readily with HNO 2 to produce NO 2, which sequentially reacted with HNO 2 to form the HNO 2–NO 2 adduct. The NO 2 + HNO 2 reaction was reversible with a forward rate constant of 3.76 × 10 7 dm 3 mol −1 s −1 and a backward rate constant of 1.06 × 10 5 s −1. Decay of the HNO 2–NO 2 adduct would most likely generate HNO 3 and NO at a rate constant of 3.0 × 10 3 s −1.