Limestone

Metal carbonates such as calcium carbonate break down when heated strongly. This is called thermal decomposition. Here are the equations for the thermal decomposition of calcium carbonate:

calcium carbonate  calcium oxide + carbon dioxide

CaCO₃ CaO + CO₂

Other metal carbonates decompose in the same way. Here are the equations for the thermal decomposition of copper carbonate:

copper carbonate  copper oxide + carbon dioxide

CuCO₃ CuO + CO₂

Calcium carbonate also reacts with acid to make a calcium salt, carbon dioxide and water.

calcium carbonate + sulphuric acid → calcium sulphate + carbon dioxide + water

CaCO3 + H2SO4 → CaSO4 + CO2 + H2O

The type of salt produced depends on the type of acid. For example a reaction with hydrochloric acid would make a chloride (e.g. CaCl2)

Other carbonates that react with acids are magnesium, copper, zinc and sodium.