Question

A given liquid changes into the gaseous state at a fixed temperature as well as at all
temperatures
(1) Name the process that takes place in each of the above two cases
(2) Mention two points of difference between the two cases in (1) above. ​

Answer 1

ANSWER: 1.At fixed temperature process is called Boiling.

At any temperature below boiling point it is called Evaporation.

2.Evaporation:

Definition:

"Evaporation is the changing of liquid into vapours from the surface of liquid without heating it."

Temperature:

Evaporation takes place at all temperature.

Place of Occurance:

Evaporation occurs only from the surface of liquid.

Boiling:

Definition:

"Boiling is the rapid vapourization of liquid into vapours at the boiling point of liquid,the temperature at which vapour pressure of liquid becomes equal to atmospheric pressure."

Temperature:

Boiling occurs at a fixed temperature called Boiling Point of liquid.

Place of Occurance:

Boiling occurs from the surface of liquid as well as within the liquid.