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

Short/Brief Note

When air is blown above the liquid, the speed by which the vapours move increases. Hence the rate of evaporation increases.
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.
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.

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Change of Liquid into Vapour State

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Chapter 6: Heat Transfer - Short/long Answer Questions [Page 120]

Chapter 6 Heat Transfer
Short/long Answer Questions | Q 9.1 | Page 120

Boiling occurs at ....................

Evaporation takes place at ................. .

Cooling is produced in ....................

Match the column

Column A	Column B
(a) Blowing air increases	(1) Increase in intermolecular separation
(b) Increase in pressure increases	(2) Pendulum of a clock
(c) Thermal expansion	(3) Cooking utensils
(d) Invar	(4) Boiling point
(e) Pyrex glass	(5) Evaporation

During boiling or vaporization

The boiling point of a liquid is increased by

No heat is supplied to a liquid during evaporation. How does then the liquid change into its vapours?

Why is cooling produced when a liquid evaporates?

What is boiling? Explain it on the basis of molecular motion?

Name two ways of change of liquid state to the vapour state and distinguish them.