Question

A farmer has sprayed a layer of cetyl alcohol on the surface of water of farm lake .Why?

Answer 1

This is because cetyl alcohol acts as a chemical cover and helps in preventing the water from the lake being evaporated.

When the alcohol is sprayed on the water, a one-molecule-thick oily layer is formed on the water surface and slows down the rate of evaporation. However, this layer degrades very soon. Thus, the cetyl alcohol layers will have to be applied once in two to four days to ensure that the water does not get evaporated.

Answer 2

The farmers spread a layer of cetyl alcohol on the surface of a farm lake to stop the evaporation of water. Research has shown that mono-layers of cetyl alcohol help in reducing up to 30 percent of the evaporation of water from open water storages.            

The different techniques used for this are:

1. The most efficient method is to dust the surface with dry, finely powdered cetyl alcohol.

2. Another method involves drip dispensing the cetyl alcohol solution in a volatile petroleum solvent.

3. It can be done by mooring gauze rafts on the surface of the water. These contain solid pellets of cetyl alcohol.