Classify each of the following, as a physical or a chemical change. Give reasons. (a) Drying of a shirt in the sun. (b) Rising of hot air over a radiator. (c) Burning of kerosene in a lantern. (d) Change in the colour of black tea on adding lemon juice to it. (e) Churning of milk cream to get butter.

Question

Philoid · Accepted Answer

(a) Drying of a shirt in the sun is a physical change because evaporation of water takes place but no change occurs in the composition of the substance.
(b) Rising of hot air over a radiator is a physical change because it is involving the only movement of air, no change in the composition of air.
(c) Burning of kerosene in a lantern is a chemical change because kerosene burns to form carbon dioxide and water vapour.
(d) Change in the colour of black tea on adding lemon juice to it is a chemical change as a new substance with chemical properties are formed.
(e) Churning of milk cream to get butter is a physical change as there is no change in composition. Only the separation of components takes place by the physical phenomenon called centrifugation.

Classify each of the following, as a physical or a chemical change. Give reasons.(a) Drying of a shirt in the sun.(b) Rising of hot air over a radiator.(c) Burning of kerosene in a lantern.(d) Change in the colour of black tea on adding lemon juice to it.(e) Churning of milk cream to get butter.