# An organic compound 'A' produces a gas with brisk effervescence when sodium bicarbonate is added to it. The compound 'A' contains the same number of carbons as in ethane. The compound 'A' reacts with ethanol to form a sweet smelling compound 'C' in presence of conc. H2SO4? acid. Then the name of compound A and the gas evolved is (1) Ethanoic acid ; CO2 (2) Methanoic acid ; CO2 (3) Ethanoic acid ; H2 (4) Methanoic acid ; H2

The compound A contains the same number of carbon as ethane.

Number of carbon atom in A compound = 2

When sodium bicarbonate is added A produces brisk effervescence. This is evidence that carbon dioxide is liberated.

CH3COOH + NaHCO3→ CH3COONa + CO2+ H2O

Sweet-smelling compounds are esters which are used in the perfume industry. Esters can be prepared by treating alcohol with an acid in the presence of conc.H2SO4. The process is called esterification.

Compound A (Ethanoic acid) + Alcohol ⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⋅⟩ Ester + Water

(Conc.H2SO4)

$CH_{3}COOH + C_{2}H_{5}OH \overset{Conc.H_{2}SO_{4}}{→} CH_{3}COOCH_{2}CH_{3} + H_{2}O$

Therefore Compound A is ethanoic acid and gas liberated is CO2.