(a) Write the structures of A and B in the following reactions :
(i) `CH_(3)COCl overset(H_2, Pd-BaSO_(4))(to)A overset(H_(2)N-OH)(to)B`
(ii) `CH_(3)MgBr overset(1.CO_(2))underset(2.H_(3)O^+)(to)A overset(PCl_(5))(to)B`
(b) Distinguish between :
(i) `C_(6)H_(5)-COCH_(3) " and "C_(6)H_(5)-CHO`
(ii) `CH_(3)COOH " and " HCOOH`
(c) Arrange the following in the increasing order of their boiling points :
(i) `CH_(3)CHO, CH_(3)COOH, CH_(3)CH_(2)OH`

Explanation

(a) (i)
(ii) `CH_(3)MgBr overset(CO_(2))underset(H_(3)O^(+))(to) CH_(3)underset((A))(COOH) overset(PCI)(to) CH_(3)overset(underset(||)(C))underset((B))(C)-CI`
(b) (i) Acetophenone and Benzaldehyde

Iodoform test

(ii) `CH_(3)COOH " and " HCOOH`
Formic acid decolourises the Pink colour of acidified `KMnO_(4)` solution, while acetic acid does not give this lest.
`5HCOOH + 2KMnO_(4) + 3H_(2)SO_(4) to K_(2)SO_(4) + 5CO_(2) + 8H_(2)O`
`CH_(3)COOH overset(KMnO_(4)//H^(+))(to)` Does not discharge pink colour of `KMnO_(4)` solution.
(c) `CH_(3)COOH gt CH_(3)CH_(2) gt OH gt CH_(3)CHO`
Reason : Because of stronger hydrogen bonding in acid the boiling point of carboxylic acids of comparable molecular mass is higher than that of alcohols.