Absorption of chlorine into aqueous bicarbonate solutions and aqueous hydroxide solutions

The absorption of Cl 2 into aqueous bicarbonate and aqueous hydroxide solutions was studied both experimentally and theoretically. The rate coefficient of the reaction between Cl 2 and OH − was estimated over the temperature range of 293–312 K and fitted by the Arrhenius equation:\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{24} = 3.56*10^{11} \exp \left({\frac{{ - 1,617}}{T}} \right) $$\end{document} . If Cl 2 were assumed to react only with water and OH − in an aqueous bicarbonate solution, the predicted absorption rate would be much lower than that experimentally measured. This suggests that Cl 2 reacts with HCO 3 − in an aqueous bicarbonate solution. The rate coefficient of the reaction between Cl 2 and HCO 3 − was estimated over the temperature range of 293–313 K and fitted by the Arrhenius equation:\documentclass{article}\pagestyle{empty}\begin{document}$$ k_{21} = 5.63*10^{10} \exp \left({\frac{{ - 4,925}}{T}} \right) $$\end{document} . More importantly, under absorption conditions, the amount of hydroxide consumed for absorbing a specific amount of Cl 2 into an aqueous hydroxide solution is almost twice the amount of bicarbonate consumed for absorbing the same amount of Cl 2 into an aqueous bicarbonate solution.