Question

how will you prove the presence of diffused air in freash water

Answer 1

First of you need to understand what diffused air is:

Diffused air in water is gas that has dissolved in water.

The simplest way to prove whether fresh water has diffused air is through heating. When you heat fresh water that has diffused air the water will form bubbles which will then escape through the surfce if not harvested. Once you heat the water the bubbles of air will rise to the surface to escape into the air.

Answer 2

At the point when water is warmed, air pockets are shaped in water, which tends to escape to the surface. This demonstrates air is available in water. The water really comprises of broke down gasses along these lines, on warming, they end up noticeably lighter and ascend to the surface and attempt to escape into the air, bringing about the development of air pockets.