Which of the following structure is correctly drawn according to fundamental idea of VSEPR theory?

Options

A.
B.
C.
D.

Answer

To determine which structure is correctly drawn according to the VSEPR (Valence Shell Electron Pair Repulsion) theory, we need to analyze the given molecular structures one by one based on their hybridization and geometry.

### Step-by-Step Solution:

1. **Analyze PF3 (Phosphorus Trifluoride):**
- **Valence Electrons Calculation:**
- Phosphorus (P) has 5 valence electrons.
- Each Fluorine (F) has 1 valence electron, and there are 3 Fluorine atoms.
- Total = 5 (P) + 3 (F) = 8 valence electrons.
- **Hybridization:**
- Hybridization = (Number of valence electrons + Number of monovalent atoms - Cations + Anions) / 2
- Here, it is (5 + 3 - 0 + 0) / 2 = 4 → sp³ hybridization.
- **Geometry:**
- sp³ hybridization corresponds to a tetrahedral geometry.
- However, due to the presence of lone pairs, the bond angles will be less than 109.5°.
- **Conclusion:**
- The structure is not correctly drawn as it suggests bond angles greater than 109.5°.

2. **Analyze SF4 (Sulfur Tetrafluoride):**
- **Valence Electrons Calculation:**
- Sulfur (S) has 6 valence electrons.
- Each Fluorine (F) has 1 valence electron, and there are 4 Fluorine atoms.
- Total = 6 (S) + 4 (F) = 10 valence electrons.
- **Hybridization:**
- Hybridization = (6 + 4 - 0 + 0) / 2 = 5 → sp³d hybridization.
- **Geometry:**
- sp³d hybridization corresponds to a trigonal bipyramidal geometry.
- The structure should have bond angles of 120° and 90°.
- **Conclusion:**
- The structure is incorrectly drawn as it does not represent the correct bond angles.

3. **Analyze ICl4⁻ (Iodine Tetrachloride Anion):**
- **Valence Electrons Calculation:**
- Iodine (I) has 7 valence electrons.
- Each Chlorine (Cl) has 7 valence electrons, and there are 4 Chlorine atoms.
- Plus, there is 1 extra electron due to the negative charge.
- Total = 7 (I) + 4*7 (Cl) + 1 = 30 valence electrons.
- **Hybridization:**
- Hybridization = (7 + 4 - 0 + 1) / 2 = 6 → sp³d² hybridization.
- **Geometry:**
- sp³d² hybridization corresponds to an octahedral geometry, but with 4 bonded pairs and 2 lone pairs, it forms a square planar shape.
- **Conclusion:**
- The structure is correctly drawn as it maintains the correct bond angles of 90°.

4. **Analyze SiF4 (Silicon Tetrafluoride):**
- **Valence Electrons Calculation:**
- Silicon (Si) has 4 valence electrons.
- Each Fluorine (F) has 1 valence electron, and there are 4 Fluorine atoms.
- Total = 4 (Si) + 4 (F) = 8 valence electrons.
- **Hybridization:**
- Hybridization = (4 + 4 - 0 + 0) / 2 = 4 → sp³ hybridization.
- **Geometry:**
- sp³ hybridization corresponds to a tetrahedral geometry.
- **Conclusion:**
- The structure is incorrectly drawn as it suggests a square planar shape instead of tetrahedral.

### Final Conclusion:
The only structure that is correctly drawn according to the VSEPR theory is **ICL4⁻**.