Question

Which amongst the following can be observed when zinc granules are added to a test tube containing dilute hydrochloric acid?

• A. No change takes place
• B. The solution turns yellow
• C. A pungent-smelling gas evolves
• D. Small bubbles are formed

Answer 1

The correct option is D Small bubbles are formed

Zinc being more reactive than hydrogen, displaces it from hydrochloric acid. As a result, tiny bubbles of hydrogen gas are formed.
$\mathrm{Zn}\left(s\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{ZnCl}}_2\left(\mathrm{aq}\right)+H_2\left(g\right)$