Question

A compound C (molecular formula, C2H4O2) reacts with Na-metal to form a compound R and evolves a gas which 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 C3H602). 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

Compound are as follows :-
C = Ethanol (Hydrogenation reaction )
R = Ethen ( addition reaction )
A = Ester ( esterification )
S = ?

Answer 2

Compound C is ethanoic acid (CH3COOH).
On reacting with Na metal :
2CH3COOH (l) + 2Na(s) ---> 2CH3COONa (aq) + H2(g)
It forms a compound R that is sodium ethanoate and evolves a gas which is hydrogen which burns with a pop up sound.

Compound C that is ethanoic acid on treatment with alcohol A that is methanol:
CH3COOH + CH3OH --> CH3COOCH3 +H2O
It gives a sweet smelling Ester S that is methyl ethanoate.

On addition of NaOH to C (ethanoic acid) :
CH3COOH + NaOH ---> CH3COONa + H2O
It gives R that is sodium ethanoate and water.

S (methyl ethanoate) on treatment with NaOH solution :
CH3COOCH3 + NaOH --> CH3COONa + CH3OH
It gives back R that is sodium ethanoate and A that is methanol.

So, 'C'is ethanoic acid, 'R' is sodium ethanoate, 'A' is methanol and 'S' is methyl ethanoate.