Question

A compound C (molecular formula, C₂H₄O₂) reacts with Na metal to form a compound R and evolves a gas that burns with a pop sound. Compound C on treatment with an alcohol A in presence of an acid forms a sweet-smelling compound S (molecular formula, C₃H₆O₂). On addition of NaOH to C, it also gives R and water. S on treatment with NaOH solution gives back R and A. Identify C, R, A, S and write down the reactions involved.

Answer 1

C — Ethanoic acid

R — Sodium salt of ethanoic acid (sodium acetate) and gas evolved is hydrogen 

A — Methanol 

S — Ester (Methyl acetete) 

(a) 2CH₃COOH + 2Na → 2CH₃COO Na + H₂

 (b) \(CH_3COOH+NaOH\overset{Conc.H_2SO_4}\rightarrow CH_3COOCH_3+H_2O\)

(c) CH₃COOH + NaOH → CH₃COONa + H₂O

(d) CH₃COOCH₃ + NaOH → CH₃COONa + CH₃OHa