Question

Hydrogen gas is obtained in the laboratory by:

• A. action of dil.$H_{2}S{O}_4$ on zinc granules
• B. action of dil.$H_{2}S{O}_4$ on aluminum foil
• C. action of dil.$H_{2}S{O}_4$ on copper chips
• D. action of dil.$H_{2}S{O}_4$ on iron fillings

Answer 1

The correct option is A

action of dil.$H_{2}S{O}_4$ on zinc granules

Hydrogen can be obtained in the laboratory by the action of the dilute sulphuric acid or dilute hydrochloric acid on zinc granules.

Take zinc granules in a wolf's bottle and fix a two-holed cork. Now from one hole fit a thistle funnel and from the second hole of cork fix delivery tube. Now add dilute sulphuric acid through thistle funnel.
Dil.$H_{2}S{O}_4$ reacts with zinc to liberate $H_2$ gas. This released gas is collected by downward displacement of water.

Though zinc, aluminium and iron being more reactive than hydrogen can replace it, but in laborotary zinc is most commonly used for hydrogen synthesis.