Question

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

• A. No change takes place
• B. The colour of the solution turns yellow
• C. A pungent smelling gas is liberated
• D. Small bubbles are formed

Answer 1

The correct option is D Small bubbles are formed

When zinc granules are added to dilute hydrochloric acid taken in a test tube, the zinc metal displaces the hydrogen from the acid and hydrogen gas comes out in the form of small bubbles. This is a displacement reaction. It occurs as follows:

$\mathrm{Zn}\left(s\right)+2\mathrm{HCl}\left(\mathrm{aq}\right)\to {\mathrm{ZnCl}}_2\left(\mathrm{aq}\right)+H_2\left(g\right)\mathrm{Zinc}\mathrm{Hydrochloric}\mathrm{Zinc}\mathrm{Hydrogen}\mathrm{acid}\mathrm{chloride}$