Question

What is the downward displacement of water?

Answer 1

Downward displacement of water refers to the displacement of water in a downward direction. It is used to collect the gas which is insoluble in water and less dense as compared to water.

Example: Collection of hydrogen

• When sodium came in contact with water it reacts with it to form hydrogen gas.
• The reaction of sodium with water is highly exothermic and thus the hydrogen gas produced catches fire on the surface of the water.
• Hydrogen is collected by downward displacement of water because it is less dense than water and so it comes out at the surface of the water also it is insoluble in water so it does not dissolves and nearly all the gas released may be collected by this process.