Hydration of NaHCO3, KHCO3, ()2, and from molecular dynamics simulation and speed of sound measurements

Car–Parrinello molecular dynamics and acoustic method have been applied to determine the hydration of HCO 3 - and CO 3 2 - ions in aqueous solution. From CPMD simulations the hydration numbers are 5.3 and 8.5 for the HCO 3 - and CO 3 2 - ions, respectively. From speed of sound and density measurements the hydration numbers for HCO 3 - and CO 3 2 - are 5.5 and 10.2, respectively. Our attempt to answer the old question concerning the status of HCO 3 - in solution quite well support the earlier spectroscopic results that no ( HCO 3 - )2 is present in the solution but the existence of the minor amount of dimers cannot be definitely excluded.