Explain the action of dilute hydrochloric acid on the following with chemical equation.
(a) Magnesium ribbon (b) Sodium hydroxide
(c ) Crushed egg shells

Explanation

(i) Dilute hydrochloric acid reacts with magnesium to form magnesium chloride and `H_2` gas is liberated.
`Mg(s)+2HCl(aq) to MgCl_2(aq)+H_2(g)`
(ii) Reaction between dilute hydrochloric acid and sodium hydroxide is a neutralisation reaction. Sodium chloride salt and water are formed.
`NaOH(aq)+HCl(aq) to NaCl(aq)+H_2O(l)`
(iii) Egg shells are made of calcium carbonate, `CaCO_3` Dilute hydrochloric acid dissolves the `CaCO_3 ` and makes the shell soft.
`CaCO_3(s)+HCl(aq) to CaCl_2+CO_2(g)+H_2O(l)`
(Crushed egg shell)