* Hydrolysis: When bicarbonate dissolves in water, it undergoes hydrolysis, reacting with water molecules to form carbonic acid (H2CO3) and hydroxide ions (OH-):
HCO3- + H2O ⇌ H2CO3 + OH-
* Hydroxide Ions: The formation of hydroxide ions, which are basic, raises the pH of the solution.
* Carbonic Acid: Carbonic acid is a weak acid, but it is in equilibrium with bicarbonate and water. This means that it does not completely dissociate, and some of it remains in its undissociated form.
Overall: The net effect of adding bicarbonate to water is an increase in pH because the formation of hydroxide ions outweighs the formation of hydrogen ions (H+) from the weak acid carbonic acid. This makes the solution more alkaline.
Key Point: The extent to which pH changes depends on the concentration of bicarbonate. Higher concentrations lead to a more significant increase in pH.
