Question

Which of the following compound on nitration gives higher percentage of para-subtituted product?

• A.
• B.
• C.
• D.

Answer 1

The correct option is B

Here inductive effect of substituents plays a major role.
-I effect increases as electronegativity increases, thus, it decreases the stability of $\sigma$-complex. Since I-effect is a distance-dependent effect, so it is higher on ortho
position than the para position.
Hence, $F$ atom have a higher –I effect than other halogens, on ortho position than para position.
Therefore, % of para product on nitration of Fluorobenzene is more.