Question

Hydrochloric acid reacts with a metal X to form a gas Y which bums with a ‘pop’ sound. Sodium hydroxide solution also reacts with the same metal X (on heating) to form the same gas Y.
(a) Name X and Y
(b) Write the chemical equation of the reaction of metal X with (i) hydrochloric acid, and (ii) sodium hydroxide solution.

Lakhmir Singh Chemistry Class 10

Answer 1

Answer:

For a: X is Zinc metal and Y is hydrogen gas.

For b: The chemical reactions are given below.

Explanation:

For a & b:

When a metal reacts with hydrochloric acid, it produces a gas Y which produces a pop sound. This sound is produced by hydrogen gas.

When the same metal is reacted with a base like sodium hydroxide, on heating it produces the same gas.

Zinc metal reacts with both acid and base (on heating) and it produces hydrogen gas.

So, X is zinc metal and Y is hydrogen gas.

The chemical equations for the reactions above are:

(i): $Zn(s)+2HCl(aq.)\rightarrow ZnCl_2(s)+H_2(g)$

(ii): $Zn(s)+2NaOH(aq.)\rightarrow Na_2ZnO_2(s)+H_2(g)$

Answer 2

(a) Metal X is Zinc and Y is hydrogen gas

(b) i) Zn + 2 HCl -> ZnCl2 + H2

ii) Zn + 2NaOH -> Na2ZnO2 + H2