Calcium hydrogencarbonate, also known as calcium bicarbonate, is a salt that can behave as either an acid or a base, depending on the context. In aqueous solutions, it undergoes partial hydrolysis, meaning that it reacts with water to produce both acidic and basic components.

The hydrolysis of calcium hydrogencarbonate can be represented by the following equation:

Ca(HCO3)2 + H2O ⇌ CaCO3 + H2CO3

In this reaction, calcium hydrogencarbonate reacts with water to form calcium carbonate, which is insoluble and precipitates out of the solution, and carbonic acid (H2CO3), which is a weak acid.

Because of the formation of carbonic acid, solutions of calcium hydrogencarbonate exhibit a slightly acidic pH. Typically, the pH of calcium hydrogencarbonate solutions ranges from 6.5 to 7.5.