The reversible interactions of dissolved CO2 with H2O and OH- to form H2CO3 and HCO3- in aqueous solution have been investigated using spectrophotometric stopped-flow measurements. The progress of the reactions was monitored via indicators coupled to the pH changes during the reactions, The study, involving global analysis of the complete data set, spanned the temperature range 6.6-42.8 degrees C and resulted in the evaluation of all rate and equilibrium constants as well as activation parameters for the kinetic data and the reaction enthalpies and entropies for the equilibrium constants.