Which is mismatched regarding the shape?

Options

A. `XeF_(4)` - Square planar
B. `XeOF_(4)` - Square pyramidal
C. `XeF_(6)` - Distorted octahedral
D. `Xe O_(3) `- Bent T shape

Answer

To determine which of the given compounds is mismatched regarding their shapes, we will analyze each compound step by step.

### Step 1: Analyze XeF4
1. **Valence Electrons Calculation**: Xenon (Xe) has 8 valence electrons, and each fluorine (F) has 1 valence electron. For XeF4, there are 4 fluorine atoms.
\[ \text{Total Valence Electrons} = 8 + (4 \times 1) = 12 \]
2. **Steric Number Calculation**: The steric number is calculated as:
\[ \text{Steric Number} = \frac{\text{Total Valence Electrons} - \text{Lone Pair Electrons}}{2} \]
In XeF4, there are 2 lone pairs (as it has 4 bonding pairs with F). Thus:
\[ \text{Steric Number} = \frac{12 - 4}{2} = 6 \]
3. **Hybridization**: The hybridization corresponding to a steric number of 6 is sp³d².
4. **Shape**: The shape of XeF4 is square planar, which is correct.

### Step 2: Analyze XeOF4
1. **Valence Electrons Calculation**: Xenon has 8 valence electrons, oxygen (O) has 6, and there are 4 fluorine atoms.
\[ \text{Total Valence Electrons} = 8 + 6 + (4 \times 1) = 18 \]
2. **Steric Number Calculation**: In XeOF4, there are 5 bonding pairs (4 F and 1 O) and 1 lone pair.
\[ \text{Steric Number} = \frac{18 - 2}{2} = 8 \]
3. **Hybridization**: The hybridization for a steric number of 6 is sp³d².
4. **Shape**: The shape of XeOF4 is square pyramidal, which is correct.

### Step 3: Analyze XeF6
1. **Valence Electrons Calculation**: Xenon has 8 valence electrons and there are 6 fluorine atoms.
\[ \text{Total Valence Electrons} = 8 + (6 \times 1) = 14 \]
2. **Steric Number Calculation**: In XeF6, there are 6 bonding pairs and 1 lone pair.
\[ \text{Steric Number} = \frac{14 - 2}{2} = 7 \]
3. **Hybridization**: The hybridization for a steric number of 7 is sp³d³.
4. **Shape**: The shape of XeF6 is distorted octahedral, which is correct.

### Step 4: Analyze XeO3
1. **Valence Electrons Calculation**: Xenon has 8 valence electrons, and there are 3 oxygen atoms.
\[ \text{Total Valence Electrons} = 8 + (3 \times 6) = 26 \]
2. **Steric Number Calculation**: In XeO3, there are 3 bonding pairs and 1 lone pair.
\[ \text{Steric Number} = \frac{26 - 2}{2} = 12 \]
3. **Hybridization**: The hybridization for a steric number of 4 is sp³.
4. **Shape**: The shape of XeO3 is pyramidal, but it is often described as bent or T-shaped due to the presence of lone pairs.

### Conclusion
The mismatched compound regarding its shape is **XeO3**, which is incorrectly described as bent or T-shaped in the question. The correct shape is pyramidal.

### Final Answer
**D. XeO3 (mismatched shape)**

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