(a) An organic co

(a) The compound with molecular formula C₇H₆O forms a 2,4-DNP derivative and reduces Tollen's reagent, so it is an aldehyde. It undergoes Cannizzaro reaction, so the aldehyde group will be directly attached to the benzene ring. On oxidation it gives benzoic acid. So, the compound will be benzaldehyde. The reactions are as follows-

C₆H₅CHO + 2[Ag(NH₃)₂]⁺ + 3OH^- → C₆H₅COO^- + 2Ag + 4NH₃ + 2H₂O

(Benzaldehyde)

2C₆H₅CHO ^{conc. NaOH}→ C₆H₅COONa + C₆H₅CH₂OH

(Benzaldehyde) (sodium benzoate) (benzyl alcohol)

C₆H₅CHO ^(O)→ C₆H₅COOH

(Benzoic acid)

(b) (i) C₆H₅OH + FeCl₃ → C₆H₅O-FeCl₂

(Phenol) (Violet color complex)

CH₃CH₂CH₂OH + FeCl₃ → no reaction

(propanol)

(ii) C₆H₅COOH + NaHCO₃→ C₆H₅COONa + CO₂ + H₂O

(benzoic acid) (brisk effervesence)

C₆H₆ + NaHCO₃→ no reaction

(benzene)

OR

(a) A = CH₃COOH (oxidation) → acetic acid

B = CH₃COCl → acetyl chloride

C= CH₃CONH₂→ acetamide

D = CH₃CONHBr → N- bromoacetamide

(b) Presence of EWG increases the acidity of carboxylic acid by stabilizing the negative charge of conjugate base by –I effect.

Moreover, -I effect of F is greater than that of Cl.

More the no. of EWG, more will be the acidity.

From above points, the increasing order of acidity will be

HCOOH< ClCH₂COOH<CCl₃COOH< CF₃COOH