Give one example in each case
(a) Change which occurs on heating but can be reversed.

(b) Change which occurs on heating but cannot be reversed.

(c) Change which occurs by mixing two substances, but can be reversed.

(d) Change which occurs by mixing two substances, but cannot be reversed.

Question

Philoid · Accepted Answer

(a) Expansion of metal rim on heating, which contracts back on cooling down.

(b) Baking of a cake, which requires heating, but the contents cannot be got back in their original form.

(c) Mixing of salt in water. The substances can be separated by evaporation of water.

(d) Mixing of sugar in milk. These substances cannot be separated out, once mixed together.

Give one example in each case(a) Change which occurs on heating but can be reversed.(b) Change which occurs on heating but cannot be reversed.(c) Change which occurs by mixing two substances, but can be reversed.(d) Change which occurs by mixing two substances, but cannot be reversed.