(a) Write the product (s) in the following reactions:
(i)
(iii) `CH_(3)-CH=CH-CN underset((b)H_(2)O)overset((a)"DIBAL-H")to`
(b) Give simple chemical tests to distinguish betweenn the following pairs of compounds:
(i) Butanal and Butan-2-one
(ii) Benzoic acid and Phenol

Explanation

(a) (i)
(ii)
(iii) `CH_(3)-CH=CH-CN underset(H_(2)O)overset(DIBAL-H)toCH_(3)CH=CH-CHO`
(b) (i) Butanal and Butan-2-one
`CH_(3)CH_(2)CH_(2)CHO" "CH_(3)-CH_(2)-underset(O)underset(||)(C)-CH_(3)`
Tollen's test
`CH_(3)CH_(2)CH_(2)CHO+2[Ag(NH_(3))_(2)]^(+)+3OH^(-)toCH_(3)CH_(2)CH_(2)COO^(-)+underset(("Silver mirror"))(2Agdarr+2H_(2)O+4NH_(3))`
`CH_(3)-CH_(2)-underset(O)underset(||)(C)-CH_(3)underset("reagent")overset("Tollen's")to` no action
(ii) Benzoic acid and Phenol
`FeCl_(3)` test:
`underset("Phenol")(C_(6)H_(5)OH)+FeCl_(3)to`Violet colouration
`underset(("Benzoic acid"))(C_(6)H_(5)COOH+FeCl_(3))tounderset(("Buff coloured ppt"))((C_(6)H_(5)COO)_(3)Fe+)3HCl`