Question

Addition of 6 M HCl to which substance will NOT result in gas evolution?

(A) Al
(B) Zn
(C) K2CO3
(D) NaNO3

The answer is D but can someone explain how to get that answer, please?

Answer 1

Answer: The correct answer is Option D.

Step-by-step explanation:

The reaction of HCl with every substance given in the option follows the equations:

• Option A: Al

The reaction of aluminium with hydrochloric acid produces aluminium chloride and hydrogen gas. The equation follows:

`2Al+6HCl\rightarrow 2AlCl_3+3H_2`

Thus, this substance evolve gas on reaction.

• Option B: Zn

The reaction of zinc with hydrochloric acid produces zinc chloride and hydrogen gas. The equation follows:

`Zn+2HCl\rightarrow ZnCl_2+H_2`

Thus, this substance evolve gas on reaction.

• Option C:
  `K_2CO_3`

The reaction of potassium carbonate with hydrochloric acid produces potassium chloride, water and carbon dioxide gas. The equation follows:

`K_2CO_3+2HCl\rightarrow 2KCl+H_2O+CO_2`

Thus, this substance evolve gas on reaction.

• Option D:
  `NaNO_3`

The reaction of sodium nitrate with hydrochloric acid produces sodium chloride and nitric acid. The equation follows:

`NaNO_3+HCl\rightarrow NaCl+HNO_3`

Thus, this substance will not evolve gas on reaction.

Hence, the correct answer is Option D.

Answer 2

Answer;

D. NaNO3

Explanation;

The reaction between NaNO3 and HCl will not produce a gas, but form NaCl and HNO3.

The reaction will be;

NaNO3 + HCl → NaCl + HNO3

This shows that no gas is evolved, when NaNO3 and HCl are reacted.