Question

What type of displacement is done by collecting pure hydrogen in the laboratory;
A. Downward displacement of water
B. Downward displacement of air C. Upward displacement air
D. Upward displacement of air

Answer 1

The correct type of displacement for collecting pure hydrogen in the laboratory is:

**B. Downward displacement of air**

Hydrogen is less dense than air, so it can be collected by allowing it to rise and displacing the air downward. In practice, this method involves using an inverted gas jar or container where hydrogen gas rises to fill the space, displacing the air below.