Explain the following with reasons: [3]
a. Formation of clouds is a physical change.
b. Melting of butter to make ghee is a chemical change.

Asked by parthuspoorthy | 6th Jan, 2021, 01:18: PM

Expert Answer:

(a) Formation of clouds is a physical change because it is a phase of transformation of water from liquid to gas during water cycle and then, gas to liquid. Hence, only the physical properties of water undergo change in the formation of clouds.
 
(b) Melting of butter is a chemical change. Butter is an emulsion of fat and water. When it is heated, the emulsion breaks up and fat gets separated from water to form two layers. This fat layer separated, is usually called ghee. The properties of ghee and butter are different and we cannot get butter back from ghee.

Answered by Ramandeep | 7th Jan, 2021, 12:47: PM