Final answer:
The functional group in compound A is a carboxyl group. The chemical equation for the formation of compound B is given as A + H2OCH3COOH -> B + H2O. Compound B is an ester known as ethyl acetate.
Step-by-step explanation:
The functional group in compound A is a carboxyl group, which has the structure -COOH. In the given equation, compound A reacts with ethanoic acid (acetic acid) to form compound B, which has a sweet smell. The chemical equation for the formation of compound B is:
A + H2OCH3COOH -> B + H2O
Compound B is an ester, specifically ethyl acetate (CH3COOCH2CH3).