Which of the following statements is correct with regard to benzene substituent?

Question

Question

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DSSSB PGT Chemistry (Female) Official Paper (Held On: 06 Jul, 2018 Shift 1)

The more deactivating substituent increases the acidity
The more activating substituent decreases the acidity
The more activating substituent increases the acidity
The more deactivating substituent increases the acidity; and the more activating substituent decreases the acidity

Answer 1

CONCEPT:

Substituents and Acidity in Benzene

Substituents on a benzene ring can be classified as activating or deactivating based on their electronic effects.
Activating substituents donate electron density to the benzene ring, stabilizing the negative charge on conjugate bases, which decreases acidity.
Deactivating substituents withdraw electron density from the benzene ring, destabilizing the negative charge on conjugate bases, which increases acidity.

EXPLANATION:

Acidity in benzene derivatives is influenced by the substituents attached to the ring.
Deactivating substituents, such as nitro (-NO₂) or halogens, pull electron density away from the ring, making the molecule more acidic.
Activating substituents, such as alkyl groups or amino (-NH₂), donate electron density to the ring, making the molecule less acidic.
Thus:
- A more deactivating substituent increases acidity.
- A more activating substituent decreases acidity.

Correct Answer: Option 2 - The more activating substituent decreases the acidity.