VII3. Nuclear Magnetic Resonance Studies of the Carbon Dioxide‐Water Equilibrium

Abstract

AbstractThe classical view of the entities existing in a solution of carbon dioxide in water is that of dissolved carbon dioxide, hydrated carbon dioxide or carbonic acid, bicarbonate ion, hydronium ion, and carbonate ion, Estimates of the concentrations of all these species are available from a variety of types of measurements. Nuclear magnetic resonance studies on. the C13 isotope dissolved as carbon dioxide in water, deuterium oxide, and in sodium hydroxide solution of various concentrations have not given any results which would require the alteration of these views. Because of equipment limitations, carbonic acid has not been detected, but a maximum limit for its concentration has been set which is not inconsistent with the predictions of electrochemical data.Two most interesting questions remain unanswered by data thus far accumulated: Why is such a large proportion of the carbon dioxide in solution present in dissolved but not hydrated form; and Why is the reaction of hydration such a slow process?