Question

A sweet odour substance formed by the reaction of an alcohol and a carboxylic acid is
A.Ether
B.Ester
C.Chloroform
D.Amide

Answer 1

Hint: Before talking about the answer, we should know about the compounds alcohols and carboxylic acid. Alcohols are the organic compound that has at least one hydroxyl group $\left( -OH \right)$ . Carboxylic acid is an organic compound that has a carboxyl group which is attached to an alkyl group. In this question, the Esterification process takes place.
Complete step by step answer:
Esterification process is defined as the combination of alcohols and acid that gives ester and water.
In this process, the primary alcohol reacts with carboxylic acid in presence of sulphuric acid as a catalyst and forms an ester as a product.
Now let us see the reaction:
$C{{H}_{3}}COOH+C{{H}_{3}}C{{H}_{2}}OH\to C{{H}_{3}}COOC{{H}_{2}}C{{H}_{3}}+{{H}_{2}}O$
When this reaction takes place, it gives sweet odour that means ester is formed.
Therefore, the correct option is B that is ester.

Additional information
There are two more methods from which esterification can take place.
From acid chloride and alcohol
When acid chloride reacts with alcohol it gives ester with steamy acidic fumes of hydrogen chloride. This reaction takes place at room temperature.
From acid anhydride and alcohol
When acid anhydride reacts with alcohol it gives ester as a product. This process is relatively slower than the acid chloride and alcohol.
Esterification process is widely used in the making of perfumes, solvents of paints; it is used in pesticides, cosmetics, pharmaceuticals.

Note:
Carboxylic acid only reacts with alcohol when a strong acid is used as a catalyst because the protonation makes the carbonyl group more electrophilic which helps to react with alcohol which is a weak nucleophile.
Esters are found in oils and fat.
Their name is derived from carboxylic acid that takes part in esterification reactions.