Oxygen of mass 18 was used as a stable tracer to measure the rate of exchange between the sulfite ion and water as a function of pH and total sulfite concentration. A value for the rate constant of hydration of SOz in aqueous solution was determined. The gross rate constants kl and k-I for the overall reaction k 1 SO2 + H z 0 e H + + HS03-k-1 at 24.7 "C and ionic strength = 0.9 were evaluated from exchange results to be k-I = 2.48 0.27 x lo9 mole-' 1 s-I k, = 1.06 k 0.13 x lo's-' Also, for the first time, rate constants for the pyrosulfite equilibrium kz 2 HS03-Sz05'-+ HZO k-z were obtained kz = 7.00 + 0.21 x 1O2mole-' 1 s-' k-z = 1 0 4~-l at 24.7 "C and ionic strength = 0.9.

No abstract

No abstract

No abstract

No abstract