Properties Of Benzene

Step 1: Understanding the Concept:
Substituents on a benzene ring direct the incoming electrophile to ortho/para or meta positions. They can also activate or deactivate the ring.

Step 2: Detailed Explanation:

• -CH₃: Ortho/para directing and activating (+I effect).
• -OH: Ortho/para directing and activating (+R effect > -I effect).
• -Cl: Ortho/para directing but deactivating. Although halogens have a strong -I effect, they also have a +R effect. The -I effect dominates, making the ring less reactive, but the +R effect directs the incoming group to ortho/para positions.
• -NO₂ and -COOH: Meta directing and deactivating (-R and -I effects).

Step 3: Final Answer:
The group that is ortho/para directing and deactivating is -Cl.