Select the incorrect statement(s):

Options

A. `NH_(3)` has a highest dipole moment among `CO,NH_(3) and NF_(3)`
B. `HF` has a highest boiling point among `CH_(4),NH_(3) and HF`
C. `Cl_(2)` has a highest boiling point among `Cl_(2),Br_(2) and I_(2)`
D. `HClO_(3)` is weakest acid among `HIO_(3),HBrO_(3) and HClO_(3)`

Answer

To solve the question of identifying the incorrect statement(s) among the given options, we will analyze each statement one by one.

### Step 1: Analyze the first statement
**Statement**: Ammonia has the highest dipole moment among carbon monoxide, ammonia, and NF3.

- **Analysis**:
- Carbon monoxide (CO) has a dipole moment of 0.122 Debye.
- Ammonia (NH3) has a significant dipole moment due to the presence of a lone pair on nitrogen and three hydrogen atoms, which creates a net dipole moment directed towards nitrogen.
- NF3 has a dipole moment, but the geometry and the electronegativity of fluorine reduce its overall dipole moment compared to ammonia.

- **Conclusion**: Ammonia indeed has the highest dipole moment among the three. Therefore, this statement is **correct**.

### Step 2: Analyze the second statement
**Statement**: HF has the highest boiling point among methane, ammonia, and HF.

- **Analysis**:
- Methane (CH4) does not exhibit hydrogen bonding, hence has a low boiling point.
- Ammonia (NH3) has hydrogen bonding, which increases its boiling point.
- HF has very strong hydrogen bonding due to the high electronegativity of fluorine, resulting in the highest boiling point among the three.

- **Conclusion**: This statement is also **correct**.

### Step 3: Analyze the third statement
**Statement**: Chlorine has the highest boiling point among chlorine, bromine, and iodine.

- **Analysis**:
- The boiling points of halogens increase with molecular size due to stronger Van der Waals forces.
- Iodine (I2) has the highest boiling point, followed by bromine (Br2), and chlorine (Cl2) has the lowest boiling point.

- **Conclusion**: This statement is **incorrect**.

### Step 4: Analyze the fourth statement
**Statement**: HClO3 is the weakest acid among HIO3, HBrO3, and HClO3.

- **Analysis**:
- The acidity of these oxyacids increases with the electronegativity of the central atom.
- Chlorine is more electronegative than bromine and iodine, making HClO3 the strongest acid among the three.

- **Conclusion**: This statement is **incorrect**.

### Final Answer
The incorrect statements are **3 and 4**.

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