Question

(a) What is evaporation ? State the various factors which affect evaporation.
(b) Why does evaporation cool a liquid ?

Answer 1

(a) Evaporation is the process by which a liquid changes into vapour form, below its boiling point. The factors that affect evaporation are:
(i) Temperature
(ii) Surface area
(iii) Humidity
(iv) Wind speed

(b) Evaporation cools the surroundings and the rest of the liquid because when a liquid evaporates, it takes up the latent heat of vaporisation from the surroundings and the rest of the liquid present below the surface with which, it is in contact.