(i) Acid + Metal:
When an acid reacts with a metal, a salt and hydrogen gas are produced. For instance, hydrochloric acid (HCl) reacting with zinc (Zn) creates zinc chloride \((ZnCl_2)\) and hydrogen gas \((H_2)\):
\[
\text{Zn} (s) + 2\text{HCl} (aq) \rightarrow \text{ZnCl}_2 (aq) + \text{H}_2 (g)
\]
Main products: Zinc chloride and hydrogen gas.
(ii) Acid + Base:
An acid reacting with a base forms a salt and water. For example, hydrochloric acid (HCl) reacting with sodium hydroxide (NaOH) yields sodium chloride (NaCl) and water \((H_2O)\):
\[
\text{NaOH} (aq) + \text{HCl} (aq) \rightarrow \text{NaCl} (aq) + \text{H}_2\text{O} (l)
\]
Main products: Sodium chloride and water.
(iii) Acid + Carbonate:
When an acid reacts with a carbonate, a salt, water, and carbon dioxide gas are produced. As an example, hydrochloric acid (HCl) reacting with sodium carbonate \((Na₂CO_3)\) generates sodium chloride (NaCl), water, and carbon dioxide \((CO_2)\):
\[
\text{Na}_2\text{CO}_3 (aq) + 2\text{HCl} (aq) \rightarrow 2\text{NaCl} (aq) + \text{H}_2\text{O} (l) + \text{CO}_2 (g)
\]
Main products: Sodium chloride, water, and carbon dioxide.