Question

How will you demonstrate that the water vapor is present in air?

Answer 1

When matter converts its physical state from gaseous phase into liquid phase, then the process is known as condensation. As it is a naturally occurring phenomenon, it is widely used to generate water in larger quantities for human use.

Complete answer:
The process of condensation can also be used for the demonstration of the water vapor that is present in air. Let us consider a steel container and put the crushed ice in it and close the container. When the steel container is left undisturbed for five minutes, it is observed that tiny water droplets seem to appear outside the surface of the container.
This happened due to the air present outside the container consisting of water vapor. The particles of water vapor when come in contact with the cold surface of the steel container, the temperature of the particles decreases and due to this the gaseous phase of water gets converted into its liquid phase i.e., condensation of water vapor occurs and because of this tiny water droplets are found at the surface of container.
Hence, this proves that the water is present in the air in its vapor phase.

Note:
It is important to note that warmer air has a greater tendency to hold more water vapor as compared to that of colder air. So, when the temperature of the atmosphere increases, more water vapor is being extracted by air due to which the humidity of the surrounding increases. Hence, summers are more humid than winters.