Question

Assertion: o-nitrophenol is more acidic than meta m-Nitrophenol
Reason: o-nitrophenol has more I effect than m-Nitrophenol
A. Both assertion and reason are correct and reason is the correct explanation for assertion.
B. Both assertion and reason are correct but reason is not the correct explanation for assertion.
C. Assertion is correct but reason is incorrect
D. Assertion is incorrect but reason is correct

Answer 1

As we know that the formula of nitrophenol is $HO{{C}_{6}}{{H}_{5-x}}{{(N{{O}_{2}})}_{x}}$. We can see here that the acidity depends on the presence of electron-donating or electron-withdrawing groups at their particular positions.

Complete Solution :
- As we know that$N{{O}_{2}}$ is an electron withdrawing group, and this group when present at ortho and para position is found to pull OH electron back towards itself by a stronger resonance effect that is –R effect.
- Whereas, the $N{{O}_{2}}$ group present at the meta position is found to pull back electrons of the OH bond through a weaker effect. Therefore, we can say that ortho and para-nitrophenols are more acidic than that of para-nitrophenols. And both assertion and reason are correct.
So, the correct answer is “Option B”.

Note: - It is found that o-nitrophenol has an application that is by the delocalization of charges it provides extra stability to the compounds. Sometimes it is seen that it deactivates or activates the benzene ring towards electrophilic substitution reaction.