Question

Ethanol on heating with acetic acid in presence of few drops of sulphuric acid gives the smell of
(A)oil of wintergreen
(B)oil of mustard
(C)an ester
(D)oil of bitter almonds.

Answer 1

Hint: The ethanol belongs to an -OH group while acetic acid and sulphuric acid belongs to an acid group. Where acetic acid is a weak acid and sulphuric is a strong acid. By knowing what will happen when acid and alcohol reacts, you can easily smell that will be produced.

Complete answer:
An acid when it reacts with an alcohol, water molecule will be removed and therefore, it will give an ester.
When ethanol \[({C_2}{H_5}OH)\] reacts with acetic acid\ [(C{H_3}COOH)\] in presence of few drops of sulphuric, it will cause removal of water molecule. This leads to the formation of an organic compound called esters \[(C{H_3}COO{C_2}{H_5})\]. This process is known as esterification. The reaction is taking place in an acidic medium. This is the reversible reaction.
The esterification reaction is given below.
\[C{H_3}COOH + {C_2}{H_5}OHC{H_3}COO{C_2}{H_5} + {H_2}O\]
Here the ester formed is \[(C{H_3}COO{C_2}{H_5})\], Ethyl acetate. Esters usually have a fruity smell.
Hence, Ethanol on heating with acetic acid in presence of few drops of sulphuric acid gives the smell of an ester.

Therefore, the correct answer will be option (C)an ester.

Additional information:
Characteristics of ester:
- Ester is a chemical compound which will be derived from the acid group, -COOH group. When the H atom from the -COOH group is replaced by some alkyl group, ester is obtained.
- Ester is a functional group and it has a fruity smell.
- Ester can be used to make perfumes.
- Plastics are prepared from polyesters.
- It can be used to make soap and detergents.

Note: Not only in the presence of sulphuric acid, esters can also be formed in presence of other acid catalysts such as Hydrochloric acid. The esterification reaction which is taking place in presence of hydrochloric acid is given below.
\[C{H_3}COOH + {C_2}{H_5}OHC{H_3}COO{C_2}{H_5} + {H_2}O\]