You are given the following meterials
(i) Marble chips (ii) Dilute hydrochloric acid (iii) Zinc granules
Identify the type of reaction when marble chips and zinc granules are added separately to acid taken in tubes. Write chemical equations in each case.

Explanation

(i) Marble chips react with dilute hydrochloric acid to form calcium chloride and carbonic acid. The acid changes to `CO_(2)` and `H_(2)O` . It is a double displacement reaction.
`CaCO_(3)(s) + 2HCl(aq) to CaCl_(2)(aq) + H_(2)CO_(3)(aq) (CO_(2)+H_(2)O)`
(ii) Zinc granules react with hydrochloric acid to form zinc chloride accompanied by hydrogen gas. It is a displacement reaction.
`Zn(s) + 2HCl(aq) to ZnCl_(2)(aq) + H_(2)(g)`