Write balanced chemical equations for the following statements :
(i) NaOH solution is heated with zinc granules
(ii) Excess of carbon dioxide gas is passed through lime water
(iii) Dilute sulphuric acid reacts with sodium carbonate
(iv) Egg shells are dropped in hydrochloric acid
(v) Copper (II) oxide reacts with dilute hydrochloric acid.

Explanation

(i) `Zn(s) + 2NaOH(aq) to Na_(2)ZnO_(2)(aq) + H_(2)(g)`
(ii) `underset("(Lime water)")(Ca(OH)_(2)(aq)) + underset("(Exess)")(2CO_(2)(g)) overset("Excess")to Ca(HCO_(3))_(2)(aq)`
(iii) `Na_(2)CO_(3)(s) + H_(2)SO_(4)(dil)to Na_(2)SO_(4)(aq) + CO_(2)(g) + H_(2)O(aq)`
(iv) White coating of egg shell contains calcium carbonate. it reacts with hydrochloric acid.
`CaCO_(3)(s) + 2HCl(aq) to CaCl_(2)(aq) + CO_(2)(g) + H_(2)O(aq)`
`CuO(s) + 2HCl(dil) to CuCl_(2)(aq) + H_(2)O(aq)`