Question

Choose the correct statement regarding electrophilic substitution reaction of haloarene.
I. As the size of the substituent increases the % of para product increases​.
II. As the size of the substituent increases the % of para product decreases​.
III. As the size of the electrophile increases the % of para product increases​.
IV. As the size of the electrophile increases the % of para product decreases​.

• A. I & III
• B. I & IV
• C. II & IV
• D. III & IV

Answer 1

The correct option is A I & III

Intermediates of electrophilic substitution reaction​:
In para substituted, $E^{+}$ and Y are apart so there is negligible interaction. ​

In ortho substituted, $E^{+}$ and Y are close so there is more interaction. ​

As the size of substituent increases, percentage of para product increases because $E^{+}$ and Y are apart so there is negligible interaction betweem them.​


The % of ortho and para product formed is depicted below in table with various electrophiles.

As the size of the substituent increases the % of para product increases.

The % of ortho and para product formed is depicted below in table with various substituents.
Hence the correct option is a.