Final answer:
The compound A used to react with ethanol is acetic acid, and the reaction produced ethyl acetate (compound B) with a sweet smell. When ethyl acetate is treated with sodium hydroxide, ethanol and sodium acetate (compound C) are formed.
Step-by-step explanation:
When Shristi heated ethanol with compound A in the presence of a few drops of concentrated sulfuric acid, she obtained a sweet smelling compound B. This reaction is a classic example of an esterification reaction, where ethanol (C2H5OH) reacts with acetic acid (CH3COOH) to produce ethyl acetate (CH3COOCH2CH3) and water (H2O). Esters are commonly characterized by their sweet smell. The reaction for the formation of ethyl acetate is as follows:
CH3COOH + C2H5OH → CH3COOC2H5 + H2O
Upon treating the sweet smelling compound B (ethyl acetate) with sodium hydroxide (NaOH), a saponification reaction occurs. This reaction breaks the ester bond and yields back the original ethanol and a compound C, which is sodium acetate (CH3COONa). Hence, A is identified as acetic acid and C as sodium acetate.