Problems and exercisesPhysical Properties
1. Order by basicity
Order from most to least basic: aniline, 4-methylaniline, 4-nitroaniline and 4-chloroaniline (pKb: 9.4; 8.9; 13.0; 10.0).
2. Meta versus para
Why is 3-nitroaniline (pKb 11.5) more basic than 4-nitroaniline (pKb 13.0)?
3. The methoxy group
A para methoxy group increases the basicity of aniline (pKb 8.7), but a meta one decreases it (9.8). Explain this difference.