Which one of the following has odd electron bond ?

Options

A. `PCl_(3)`
B. `SF_(4)`
C. `PCl_(5)`
D. `POCl_(3)`

Answer

To determine which of the given compounds has an odd electron bond, we need to analyze the electron configuration of each compound. An odd electron bond occurs when there is an odd number of electrons in the molecule, which can lead to the formation of free radicals.

### Step-by-Step Solution:

1. **Understanding Odd Electron Bonds**:
- An odd electron bond is characterized by the presence of an unpaired electron in the molecule. This typically occurs in molecules where the total number of valence electrons is odd.

2. **Analyzing Each Compound**:
- Let's consider the compounds mentioned: PCl3, PCl5, and POCl3.

3. **Electron Count in PCl3**:
- Phosphorus (P) has 5 valence electrons, and each Chlorine (Cl) has 7 valence electrons.
- In PCl3, phosphorus shares 3 electrons with 3 chlorine atoms.
- Total electrons = 5 (from P) + 3*7 (from 3 Cl) = 5 + 21 = 26 electrons.
- Since 26 is even, PCl3 does not have an odd electron bond.

4. **Electron Count in PCl5**:
- In PCl5, phosphorus shares all 5 of its electrons with 5 chlorine atoms.
- Total electrons = 5 (from P) + 5*7 (from 5 Cl) = 5 + 35 = 40 electrons.
- Since 40 is even, PCl5 does not have an odd electron bond.

5. **Electron Count in POCl3**:
- In POCl3, phosphorus shares 3 electrons with 3 chlorine atoms and has a double bond with oxygen.
- Total electrons = 5 (from P) + 7 (from O) + 3*7 (from 3 Cl) = 5 + 7 + 21 = 33 electrons.
- Since 33 is odd, POCl3 has an odd electron bond.

6. **Conclusion**:
- Among the given options, POCl3 is the compound that has an odd electron bond due to the total number of electrons being odd.

### Final Answer:
The compound with an odd electron bond is **POCl3**.