Question

Two statements, One Assertion and the other Reason, are given. Which one of the following options is correct?
Assertion: The acid strength of 4 compounds in the descending order is p-Nitrophenol \( > \) p-Methoxyphenol \( > \) Phenol \( > \) p-chlorophenol.
Reason: Electron withdrawing groups increase the acid strength while Electron donating groups decrease the acid strength of Phenol and its derivatives.

• A. Assertion is correct but Reason is wrong.
• B. Both Assertion and Reason are wrong.
• C. Assertion is wrong but Reason is correct.
• D. Both Assertion and Reason are correct.

Hint:

The acid strength of phenols and their derivatives depends on the substituent groups. Electron-withdrawing groups stabilize the conjugate base, increasing the acidity, while electron-donating groups decrease the acidity by destabilizing the conjugate base.

Answer 1

The Correct Option is C

Step 1: Analyze the Assertion.
The assertion states the correct order of acid strengths based on the substituent groups attached to the phenol ring. When comparing compounds like p-Nitrophenol, p-Methoxyphenol, Phenol, and p-chlorophenol, the acid strength indeed follows the order:
\[ \text{p-Nitrophenol} > \text{p-Methoxyphenol} > \text{Phenol} > \text{p-chlorophenol}. \]
This is because electron-withdrawing groups like \( \text{NO}_2 \) (in p-Nitrophenol) increase acidity, while electron-donating groups like \( \text{OCH}_3 \) (in p-Methoxyphenol) decrease acidity.

Step 2: Analyze the Reason.
The reason provided is correct: electron-withdrawing groups (such as \( \text{NO}_2 \)) increase the acidity of phenol by stabilizing the conjugate base, while electron-donating groups (such as \( \text{OCH}_3 \)) make the conjugate base less stable, thereby decreasing the acidity.

Step 3: Conclusion.
Both the assertion and reason are correct; however, in this specific case of the assertion question, both options stand to be true. Thus, we conclude that Option (C) is the correct answer.