Question

Which of the following factors affect the basic strength of amines? 
(i) Inductive effect
(ii) Steric hindrance
(iii) Solvation effect
(iv) Solubility in organic solvents
 

• A. (i) and (iv)
• B. (i), (ii), and (iii)
• C. (ii) and (iii)
• D. (ii) and (iv)

Hint:

The basic strength of amines depends on electronic effects (+I/-I), steric hindrance, and solvation. More hindrance and less solvation decrease basicity.

Answer 1

The Correct Option is B

Step 1: Understanding the factors affecting basic strength of amines. The basicity of an amine depends on its ability to donate a lone pair of electrons on the nitrogen atom. Several factors influence this ability: Inductive Effect: Electron-donating groups (+I effect) increase electron density on nitrogen, enhancing basicity. Conversely, electron-withdrawing groups (-I effect) decrease basicity. Steric Hindrance: Bulky groups around nitrogen hinder solvation and protonation, reducing basicity. Solvation Effect: The interaction of the amine with solvent molecules affects its ability to stabilize the conjugate acid form, influencing basic strength. 
Step 2: Eliminating incorrect Option. 
- Solubility in organic solvents (Option iv) does not directly influence the intrinsic basic strength of amines. 
- Correct factors: Inductive effect (i), Steric hindrance (ii), and Solvation effect (iii) play significant roles in determining basicity. 
Thus, the correct answer is (B) (i), (ii), and (iii).