Which of the following molecule is planar as well as polar :

Options

A. `PCl_(3)`
B. `SF_(4)`
C. `ClF_(3)`
D. None of these

Answer

To determine which molecule is both planar and polar, we will analyze the given molecules: PCl3, SF4, and ClF3.

### Step 1: Analyze PCl3
1. **Valence Electrons**: Phosphorus (P) has 5 valence electrons, and each chlorine (Cl) has 7 valence electrons. Thus, PCl3 has:
- Total = 5 + (3 × 7) = 26 valence electrons.

2. **Lewis Structure**: In PCl3, phosphorus is the central atom with three chlorine atoms bonded to it and one lone pair on phosphorus.
- Structure: Cl - P - Cl
|
Cl
- This results in a trigonal pyramidal shape due to the lone pair.

3. **Polarity**: The dipole moments of the P-Cl bonds do not cancel out due to the lone pair, making PCl3 polar.

4. **Planarity**: However, PCl3 is not planar because of the lone pair causing a three-dimensional shape.

### Step 2: Analyze SF4
1. **Valence Electrons**: Sulfur (S) has 6 valence electrons, and each fluorine (F) has 7 valence electrons. Thus, SF4 has:
- Total = 6 + (4 × 7) = 34 valence electrons.

2. **Lewis Structure**: In SF4, sulfur is the central atom with four fluorine atoms bonded to it and one lone pair.
- Structure: F
|
F-S-F
|
F
- This results in a seesaw shape (or C-shaped) due to the lone pair.

3. **Polarity**: The dipole moments do not cancel out, making SF4 polar.

4. **Planarity**: However, SF4 is not planar because of the lone pair and the arrangement of the bonds.

### Step 3: Analyze ClF3
1. **Valence Electrons**: Chlorine (Cl) has 7 valence electrons, and each fluorine (F) has 7 valence electrons. Thus, ClF3 has:
- Total = 7 + (3 × 7) = 28 valence electrons.

2. **Lewis Structure**: In ClF3, chlorine is the central atom with three fluorine atoms bonded to it and two lone pairs.
- Structure:
F
|
F-Cl-F
- This results in a T-shaped structure due to the lone pairs.

3. **Polarity**: The dipole moments do not cancel out, making ClF3 polar.

4. **Planarity**: ClF3 is planar because all the atoms can be arranged in one plane.

### Conclusion
Among the given options, ClF3 is the molecule that is both planar and polar.

### Final Answer
The molecule that is planar as well as polar is **ClF3**.

---