Explain why :
(a) Respiration is na exothermic reaction.
(b) When blue salt of copper sulphate is heated, it becomes colourless.

Explanation

(a) For answer, consult Q. 10 (N.C.E.R.T. Exercise).
(b) Blue copper sulphate is heated, it becomes colourless.
(b) Blue copper sulphate is crystalline in nature and contains five `H_(2)O` molecules `(CuSO_(4).5H_(2)O)` Upon heating, it loses all the `H_(2)O` molecules and changes to `CuSO_(4)` which is colourless.
`{:(CuSO_(4) 5H_(2)O (s) overset("heat")to, CuSO_(4) (s) + 5H_(2)O(g)),(" ""(Blue)", "(Colourless)"):}`