Question

Rank the following compounds in order of increasing basicity.

• A. 4<2<1<3
• B. 4<1<3<2
• C. 4<3<1<2
• D. 2<1<3<4

Hint:

Remember that electron-donating groups increase basicity, while electron-withdrawing groups decrease basicity.

Answer 1

The Correct Option is C

In this case, the basicity of the compounds is influenced by the electron-withdrawing or electron-donating groups attached to the benzene ring. The amino group (-NH\(_2\)) is an electron-donating group, which increases the basicity of the compound. 
In contrast, electron-withdrawing groups like -NO\(_2\) or -Cl will decrease the basicity of the compound. 

- Compound 1: The amino group (-NH\(_2\)) is electron-donating, increasing the basicity. 
- Compound 2: The -Cl group is electron-withdrawing, making the compound less basic. 
- Compound 3: The -NO\(_2\) group is strongly electron-withdrawing, further decreasing basicity compared to compound 2. 
- Compound 4: The amino group (-NH\(_2\)) is present again, but the -NO\(_2\) group is also attached, significantly reducing its basicity. 

Thus, the order of increasing basicity is: 4<3<1<2.