a. Give chemical tests to distinguish between the following:
(i) Benzoic acid and ethyl benzoate,
(ii) Benzaldehyde and acetophenone
b. Complete each synthesis by giving missing reagents or products in the following:

Explanation

a. (i) Benzoic acid and ethyl benzoate:
Sodium bicarbonate test: Warm each compound with `NaHCO_(3)` Benzoic acid gives brisk effervesence of `CO_(2)` gas whereas ethyl benzoate does not respond to this test.
(Other relevant test can be accepted)
(ii) Benzaldehyde and Acetaphenone:
Iodoform test: Warm each organic compound with `I_(2)` and NaOH solution with acetophenone `(C_(6)H_(5)COCH_(3))` yellow precipitate of iodoform is formed which responds to idoform test, whereas benzaldehyde does not respond to this test.

(ii) `C_(6)H_(5)CH="NN"HCONH_(2)`
(iii) a. `B_(2)H_(6).H_(2)O_(2)//OH` b. PCC