Question

Addition of 6 M HCl to which substance will not result in gas evolution? Please explain why.A) AlB) ZnC) K2CO3D) NaNO3

Answer 1

Answer:

Option D ($NaNO_3$)

Explanation:

Acids react with metal to form salt and hydrogen gas.

Metals which are more reactive than hydrogen evolve hydrogen gas on reaction with acid.

For example:

Magnesium reacts with hydrogen chloride to form magnesium chloride and hydrogen.

2HCl(aq) + Mg(s) → MgCl2(aq) + H2(g)

Al and Zn are more reactive than hydrogen, therefore, these metals evolve hydrogen gas on reaction with acid.

$NaNO_3$ reacts with HCl to form NaCl and nitric oxide.

$HCl+NaNO_3 \rightarrow NaCl+HNO_3$

$K_2CO_3$ reacts with HCl to form potassium chloride, carbon dioxide and water.

$HCl+K_2CO_3 \rightarrow KCl+CO_2+H_2O$

As reaction of  $NaNO_3$ does not evolve any gas, therefore, the correct option is D.