Question

Give reason for the increase in rate of evaporation of a liquid when air is blown above the liquid.

Answer 1

1. When air is blown above the liquid, the speed by which the vapours move increases. Hence the rate of evaporation increases.
2. When the surface area is increased, rate of evaporation also increases. This is because evaporation occurs among the molecules on the surface, not in the interior. This means; increasing the surface area will increase the chance of more molecules to evaporate.
3. As temperature increases, rate of evaporation also increases. This is due to increasing kinetic energy of the surface molecules which leads them to free and become vapour.