How do metal carbonates react with acids?
Ans. When a metal carbonate or metal hydrogen carbonate reacts with an acid, it forms corresponding salt and carbon dioxide gas.
$$\underset{\text{Sodium carbonate}}{Na_2CO_{3(s)}} + 2HCl_{aq} \rightarrow \underset{\text{Sodium chloride}}{2NaCl_{(aq)}} + H_2O_{(l)} + \underset{\text{carbon dioxide}}{CO_{2(g)}}$$
$$\underset{\text{Aluminium carbonate}}{Al_2(CO_3)_3} + 6HCl \rightarrow \underset{\text{Aluminium chloride}}{2AlCl_3} + 3H_2O + \underset{\text{carbon dioxide}}{3CO_{2(g)}}$$
$$\underset{\text{Sodium Bicarbonate}}{NaHCO_{3(s)}} + HCl_{(aq)} \rightarrow \underset{\text{Sodium chloride}}{NaCl_{(aq)}} + H_2O_{(l)} + \underset{\text{carbon dioxide}}{CO_{2(g)}}$$