Hence, the majority of the carbon dioxide is not converted into carbonic acid but remains as dissolved CO2 molecules. This dissolved CO2 does not affect the pH unlike the carbonic acid. The relative concentrations of CO2, H2CO3, and the deprotonated forms HCO ( J (bicarbonate) and CO ( &J (carbonate) depend on the pH. In neutral or slightly alkaline water (pH > 6.5) the bicarbonate form predominates. In very alkaline water (pH > 10.4) carbonate is the predominant form. The presence of salinity shifts the equilibrium such that the solubility of CO2 in sea water is higher than fresh water.