COMEDK2015ChemistryAmines
The correct increasing order of basic strength of following amines, C ₂ H ₅ NH ₂, NH ₃, ( C ₂ H ₅ )₂ NH ₆ C ₆ H ₅ NH ₂ in gaseous state is
Options
- A( C ₂ H ₅ )₂ NH < C ₂ H ₅ NH ₂ < NH ₃ < C ₆ H ₅ NH ₂
- BC ₆ H ₅ NH ₂ < ( C ₂ H ₅ )₂ NH < C ₂ H ₅ NH ₂ < NH ₃
- CC ₆ H ₅ NH ₂ < NH ₃ < C ₂ H ₅ NH ₂ < ( C ₂ H ₅ )₂ NH
- D( C ₂ H ₅ )₂ NH < C ₂ H ₅ NH ₂ < C ₆ H ₅ NH ₂ < NH ₃
Correct answer
C. C ₆ H ₅ NH ₂ < NH ₃ < C ₂ H ₅ NH ₂ < ( C ₂ H ₅ )₂ NH
Step-by-step solution
Aniline is less basic than ammonia and aliphatic amines due to delocalisation of lone pair of electrons on the benzene ring. Aliphatic amines are stronger bases, than ammonia due to +I -effect of alkyl group. More the number of alkyl groups stronger is the base. Hence, basic strength will follow the following order ( C ₂ H ₅ )₂ NH > C ₂ H ₅ NH ₂> NH ₃> C ₆ H ₅ NH ₂