Magnesium carbonate reacts with sulfuric acid to form magnesium sulfate and carbonic acid. It is a double displacement reaction. The balanced equation for the reaction is;
MgCO3 + H2SO4 ------ > MgSO4 + H2CO3
Carbonic acid which is produced during this reaction in unstable. So, it decomposes into carbon dioxide and water. Bubbles are produced in this redaction which indicates the production of carbon dioxide gas. The chemical equation can also be written as;
MgCO3 + H2SO4 ------ > MgSO4 + H2O + CO2
MgCO3 + H2SO4 ------ > MgSO4 + H2CO3
Carbonic acid which is produced during this reaction in unstable. So, it decomposes into carbon dioxide and water. Bubbles are produced in this redaction which indicates the production of carbon dioxide gas. The chemical equation can also be written as;
MgCO3 + H2SO4 ------ > MgSO4 + H2O + CO2