The reactivity of hydrogen atoms with ethanol and formate in aqueous solution

The ratio of the velocity constants of the reactions of H atoms (produced by irradiation of aqueous solutions) with ethanol and ferricyanide respectively has been determined. The ratio is constant between pH 1-3-3-0. In this range H atoms are the reacting species as a result of the preceding reaction e _aq^-+H_aq⁺→H. In solutions containing formic acid and ferricyanide, the velocity constant ratio changes with pH in the same range, indicating that the anion HCO₂^- reacts with H atoms faster than the acid HCO₂H. Relative velocity constants are determined. The conclusions are confirmed by comparison with results obtained using H atoms produced by dissociation of molecular hydrogen.