Question

Identify the gas evolved in each of the following cases: (i) a colorless gas liberated on decomposition of nitric acid. (ii) water is added to calcium carbide (iii) dilute hydrochloric acid is added to zinc sulphide. (iv) dilute nitric acid is added to copper?

Answer 1

The gases evolved are nitrogen dioxide when nitric acid decomposes, acetylene when water is added to calcium carbide, hydrogen sulfide when dilute hydrochloric acid is added to zinc sulphide, and nitrogen dioxide when dilute nitric acid is added to copper.

Step-by-step explanation:

Identifying the gases evolved in different reactions involves understanding the chemical processes taking place:

1. When nitric acid decomposes, it can produce nitrogen oxides, such as nitrogen dioxide (NO2), which is a brown gas.
2. Adding water to calcium carbide (CaC2) results in the production of acetylene gas (C2H2).
3. When dilute hydrochloric acid is added to zinc sulphide (ZnS), the reaction liberates hydrogen sulfide gas (H2S).
4. Adding dilute nitric acid to copper (Cu) results in the formation of copper (II) nitrate and a brown gas, which is nitrogen dioxide (NO2).

The types of gases formed depend on the reactants and the conditions of the reaction.