(a) Give chemical tests to distinguish between the following pairs of compounds:
(i) Ethanal and Propanone.
(ii) Pentan-2-one and Pentan-3-one.
(b) Arrange the following compounds in increasing order of their acid strength: Benzoic acid, 4- Nitrobenzoic acid, 3,4-Dinitrobenzoic acid,
4- Methoxybenzoic acid.

Explanation

The increasing order of acidic strength : 4-methoxybenzoic acid lt 4-nitrobenzoic acid lt 2, 4-dinitrobenzoic acid. For detailed discussion, consult section 13. 16.