Reactions of acids with carbonates

A salt, water and carbon dioxide are produced when acids react with carbonates. In general:

Acid + carbonate → salt + water + carbon dioxide

For example:

Hydrochloric acid + copper carbonate → copper chloride + water + carbon dioxide

2HCl(aq) + CuCO3(s) → CuCl2(aq) + H2O(l) + CO2(g)

Other carbonates also react with dilute acids. For example:

Sulfuric acid + magnesium carbonate → magnesium sulfate + water + carbon dioxide

H2SO4(aq) + MgCO3(s) → MgSO4(aq) + H2O(g) + CO2(g)


Name the products of the reaction of zinc carbonate with hydrochloric acid.

The products are zinc chloride, water and carbon dioxide.


Name the products of the reaction between zinc carbonate and sulfuric acid, and write a balanced symbol equation for the reaction.

The products are zinc sulfate, water and carbon dioxide.

H2SO4(aq) + ZnCO3(s) → ZnSO4(aq) + H2O(g) + CO2(g)

Testing for carbon dioxide gas

Carbon dioxide gas can be identified by bubbling it through limewater. Limewater is a dilute solution of calcium hydroxide. Limewater is colourless, but when it is mixed with carbon dioxide, it turns cloudy.