Which of the following reacts explosively with dilute hydrochloric acid to liberate hydrogen gas?

1. Aluminium

2. Magnesium

3. Zinc

4. Potassium

The correct option is D

Potassium

Explanation for the correct option -

Option (d) Potassium

• According to the activity series potassium (K) is the most reactive element.
• So Potassium will react explosively with dilute hydrochloric acid to liberate hydrogen gas.

Explanation for the incorrect option -

Option (a) Aluminium - According to the activity series, it is less reactive than potassium.

Option (b) Zinc - According to the activity series, it is less reactive than potassium.

Option (c) Magnesium - According to the activity series, it is less reactive than potassium.

Therefore, Option (d) potassium is the correct answer.