Expanded octet is present in

Options

A. `SF_(6)`
B. `PCI_(5)`
C. `IF_(7)`
D. All of these

Answer

To determine which compounds exhibit an expanded octet, we need to analyze the valence electrons of the central atom in each compound. An expanded octet occurs when a central atom has more than 8 electrons in its valence shell. Let's evaluate the compounds one by one.

### Step 1: Analyze SF6
1. **Identify the central atom**: Sulfur (S).
2. **Count the valence electrons**: Sulfur has 6 valence electrons (Group 16).
3. **Count the monovalent atoms**: There are 6 fluorine (F) atoms, each contributing 1 electron.
4. **Calculate total valence electrons**:
\[ \text{Total} = \text{Valence electrons of S} + (\text{Number of F atoms} \times 1) = 6 + 6 = 12 \]
5. **Determine hybridization**:
\[ \text{Hybridization} = \frac{\text{Total valence electrons}}{2} = \frac{12}{2} = 6 \quad \text{(sp}^3\text{d}^2\text{)} \]
6. **Check for expanded octet**: Since there are 12 electrons, SF6 has an expanded octet.

### Step 2: Analyze PCl5
1. **Identify the central atom**: Phosphorus (P).
2. **Count the valence electrons**: Phosphorus has 5 valence electrons (Group 15).
3. **Count the monovalent atoms**: There are 5 chlorine (Cl) atoms.
4. **Calculate total valence electrons**:
\[ \text{Total} = 5 + 5 = 10 \]
5. **Determine hybridization**:
\[ \text{Hybridization} = \frac{10}{2} = 5 \quad \text{(sp}^3\text{d)} \]
6. **Check for expanded octet**: Since there are 10 electrons, PCl5 has an expanded octet.

### Step 3: Analyze IF7
1. **Identify the central atom**: Iodine (I).
2. **Count the valence electrons**: Iodine has 7 valence electrons (Group 17).
3. **Count the monovalent atoms**: There are 7 fluorine (F) atoms.
4. **Calculate total valence electrons**:
\[ \text{Total} = 7 + 7 = 14 \]
5. **Determine hybridization**:
\[ \text{Hybridization} = \frac{14}{2} = 7 \quad \text{(sp}^3\text{d}^3\text{)} \]
6. **Check for expanded octet**: Since there are 14 electrons, IF7 has an expanded octet.

### Conclusion
All three compounds (SF6, PCl5, and IF7) exhibit an expanded octet as they all have more than 8 electrons in their valence shells.

### Final Answer
**Expanded octet is present in: All of the above (SF6, PCl5, IF7)**.

---