Question

Aniline dissolves in HCl due to formation of:
A. anilinium chloride
B. o-chloroaniline
C. azo dye
D. diazonium chloride

Answer 1

Hint: For this problem, we have to write the complete reaction of the aniline with hydrochloric acid and after the product is formed we have to study its nature and properties to choose the correct option.

Complete Step-by-Step answer:
- In the given question, we have to choose the correct product formed by the reaction between aniline and hydrochloric acid.
- Aniline is an organic compound which has basic nature. The molecule is formed when the amine group attaches on the benzene ring.
- Now, the hydrochloric acid as the name tells has acidic nature so when it will react with aniline the acid-base reaction will take place.
- When aniline dissolves in the hydrochloric acid then the lone pair that is present on the amine group will undergo partial delocalisation.
- Now, the amine is able to undergo the protonation by an acid that is hydrochloric acid.
- In the protonation process, the negative anion from the acid comes and attaches to the positive charge that is present on the amine.
  - Due to which the formation of the complex the aniline will dissolve in the solution of hydrochloric acid.
- The balanced chemical reaction between aniline and hydrochloric acid is:
\[{{\text{C}}_{6}}{{\text{H}}_{5}}\text{N}{{\text{H}}_{2}}\text{ + HCl }\to \text{ }{{\text{C}}_{6}}{{\text{H}}_{5}}\text{NH}_{3}^{+}\text{C}{{\text{l}}^{-}}\]
- Here, the complex formed is known as anilinium chloride.
Therefore, option A is the correct answer.

Note: Partial delocalisation of the electron is the delocalisation of the pi-electron and the effect is also known as resonance due to which the molecule becomes more stable. In ammine, there are three bond pairs whereas one lone pair.