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Assertion: Replacement fo -Cl group by -...

Assertion: Replacement fo -Cl group by -OH in chlorobenzene is easier if nitro group is present in the ring.
Reason: Nitro group leads to strengthening of the C-Cl bond in chlorobenzene.

A

If both assertion and reason are true and reason Is the correct explanation of assertion.

B

If both assertion and reason are true but reason is not the correct explanation of assertion.

C

If assetion is true but reason is false.

D

If both assertion and reason are false.

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given question, we need to analyze both the assertion and the reason provided. ### Step 1: Understanding the Assertion The assertion states that the replacement of the -Cl group by -OH in chlorobenzene is easier if a nitro group (-NO2) is present in the ring. - Chlorobenzene is a compound where a chlorine atom is attached to a benzene ring. - The process of replacing the chlorine atom with a hydroxyl group (-OH) involves a nucleophilic substitution reaction. - The presence of a nitro group, which is an electron-withdrawing group, can influence the reactivity of the chlorobenzene. ### Step 2: Analyzing the Mechanism When a nitro group is present on the benzene ring, it exerts a -M (mesomeric) effect, which stabilizes the positive charge that develops during the nucleophilic substitution reaction. - The nitro group pulls electron density away from the ring, making the carbon atom bonded to chlorine more electrophilic (positively charged). - This increased positive character on the carbon atom makes it easier for the nucleophile (OH-) to attack and replace the chlorine atom. ### Step 3: Understanding the Reason The reason states that the nitro group leads to the strengthening of the C-Cl bond in chlorobenzene. - This statement is incorrect. The presence of the nitro group actually weakens the C-Cl bond rather than strengthening it. - The electron-withdrawing effect of the nitro group destabilizes the C-Cl bond, making it easier for the bond to break during the nucleophilic substitution reaction. ### Step 4: Conclusion Based on the analysis: - The assertion is **true**: The replacement of -Cl by -OH is indeed easier if a nitro group is present. - The reason is **false**: The nitro group does not strengthen the C-Cl bond; it weakens it. ### Final Answer Thus, the correct conclusion is: - Assertion: True - Reason: False
To solve the given question, we need to analyze both the assertion and the reason provided. ### Step 1: Understanding the Assertion The assertion states that the replacement of the -Cl group by -OH in chlorobenzene is easier if a nitro group (-NO2) is present in the ring. - Chlorobenzene is a compound where a chlorine atom is attached to a benzene ring. - The process of replacing the chlorine atom with a hydroxyl group (-OH) involves a nucleophilic substitution reaction. - The presence of a nitro group, which is an electron-withdrawing group, can influence the reactivity of the chlorobenzene. ...
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