Choose the false statement

Options

A. `-NH_(2)` is strongly activating while `-NHCOCH_(3)` is activating
B. `-NO_(2)` is strongly deactivating while `-CHO` is deactivating
C. `-NHCOR` and `-CHO` are m - directing
D. `-CF_(3)` and `-COR` are m - directing

Answer

To solve the question of identifying the false statement regarding the activating and deactivating nature of functional groups attached to a benzene ring, we can break down the information systematically.

### Step 1: Analyze the Statements
We have four statements to evaluate:
1. NH2 is strongly activating while NHCOCH3 is activating.
2. NO2 is strongly deactivating and CHO is deactivating.
3. NHCOR is a meta-directing group.
4. CF3 and COR are also meta-directing groups.

### Step 2: Evaluate Each Statement
**Statement 1:** NH2 is strongly activating while NHCOCH3 is activating.
- The NH2 group (amino group) is indeed a strong activating group due to its ability to donate electron density to the benzene ring via resonance.
- The NHCOCH3 (acetanilide) is a weakly activating group, primarily due to resonance but less effective than NH2. Therefore, this statement is partially true but misleading as it suggests NHCOCH3 is strongly activating.

**Statement 2:** NO2 is strongly deactivating and CHO is deactivating.
- The NO2 (nitro group) is a strong electron-withdrawing group and indeed deactivates the benzene ring.
- The CHO (aldehyde group) is also electron-withdrawing and deactivates the ring. This statement is true.

**Statement 3:** NHCOR is a meta-directing group.
- The NHCOR group (where R is an alkyl or aryl group) is indeed a meta-directing group because it does not stabilize the positive charge at the ortho and para positions effectively due to resonance. This statement is true.

**Statement 4:** CF3 and COR are also meta-directing groups.
- The CF3 (trifluoromethyl group) is a strong electron-withdrawing group and directs substitution to the meta position.
- The COR (carbonyl group) is also a meta-directing group due to its electron-withdrawing nature. This statement is true.

### Step 3: Identify the False Statement
From the evaluation:
- Statement 1 is misleading as it implies NHCOCH3 is activating without qualification. It is weakly activating, not strongly.
- Statements 2, 3, and 4 are true.

Thus, the false statement is **Statement 1**.

### Final Answer
The false statement is: **"NH2 is strongly activating while NHCOCH3 is activating."**

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