How do acids react with metals and carbonates?

Acids react with metals to produce salt and hydrogen gas. For example:
2HCl+Zn→ZnCl2+H2↑\text{2HCl} + \text{Zn} \rightarrow \text{ZnCl}_2 + \text{H}_2 \uparrow2HCl+Zn→ZnCl2​+H2​↑
Acids also react with carbonates and hydrogen carbonates to form salt, water, and carbon dioxide gas:
HCl+Na2CO3→NaCl+H2O+CO2↑\text{HCl} + \text{Na}_2\text{CO}_3 \rightarrow \text{NaCl} + \text{H}_2\text{O} + \text{CO}_2 \uparrowHCl+Na2​CO3​→NaCl+H2​O+CO2​↑
These reactions are used in identifying carbonate compounds and releasing CO₂ in baking. Gas evolution, fizzing, or bubbling are signs of such reactions. They are also important in lab experiments and practical applications.