Amines with alkyl groups attached to the nitrogen are generally more basic because of the electron-donating effect of alkyl groups, which increases the electron density on nitrogen.
The pK\(_b\) value represents the basicity of an amine. Lower pK\(_b\) values indicate stronger bases.
- N,N-Dimethyl aniline (A) has a pK\(_b\) value of 9.30, which is the weakest base among the options, so A is matched with III.
- Aniline (B) has a pK\(_b\) value of 8.92, indicating moderate basicity, so B is matched with II.
- N-Ethylethanamine (C) has a higher basicity (pK\(_b\) value of 9.38), so C is matched with I.
- N-Methylaniline (D) has the highest basicity (pK\(_b\) value of 3.00), so D is matched with IV.
Hence, the correct matching is (1) A-II, B-III, C-IV, D-I
