Which of the following molecule is of T -shape ?

Options

A. `I_(3)^(-)`
B. `ClF_(3)`
C. `SF_(4)`
D. `XeF_(4)`

Answer

To determine which molecule is T-shaped, we need to analyze the molecular geometry of each option based on the number of bonding pairs and lone pairs around the central atom. Here’s a step-by-step breakdown:

### Step 1: Identify the Central Atom and Count Lone Pairs and Bonding Pairs
For each molecule, identify the central atom and count the number of lone pairs and bonding pairs.

1. **I3- (Iodine triiodide ion)**:
- Central atom: Iodine (I)
- Lone pairs: 3
- Bond pairs: 2

2. **ClF3 (Chlorine trifluoride)**:
- Central atom: Chlorine (Cl)
- Lone pairs: 2
- Bond pairs: 3

3. **SF4 (Sulfur tetrafluoride)**:
- Central atom: Sulfur (S)
- Lone pairs: 1
- Bond pairs: 4

4. **XeF4 (Xenon tetrafluoride)**:
- Central atom: Xenon (Xe)
- Lone pairs: 2
- Bond pairs: 4

### Step 2: Calculate the Steric Number
The steric number is calculated as the sum of the number of bond pairs and lone pairs.

- **I3-**: Steric number = 2 (bond pairs) + 3 (lone pairs) = 5
- **ClF3**: Steric number = 3 (bond pairs) + 2 (lone pairs) = 5
- **SF4**: Steric number = 4 (bond pairs) + 1 (lone pair) = 5
- **XeF4**: Steric number = 4 (bond pairs) + 2 (lone pairs) = 6

### Step 3: Determine Hybridization
Based on the steric number, we can determine the hybridization:

- **I3-**: Steric number 5 → sp³d hybridization
- **ClF3**: Steric number 5 → sp³d hybridization
- **SF4**: Steric number 5 → sp³d hybridization
- **XeF4**: Steric number 6 → sp³d² hybridization

### Step 4: Identify Molecular Geometry
Using the VSEPR theory, we can predict the molecular geometry:

- **I3-**: With 3 lone pairs in equatorial positions, the shape is linear (triangular bipyramidal geometry).
- **ClF3**: With 2 lone pairs and 3 bond pairs, the shape is T-shaped (triangular bipyramidal geometry).
- **SF4**: With 1 lone pair and 4 bond pairs, the shape is seesaw (triangular bipyramidal geometry).
- **XeF4**: With 2 lone pairs and 4 bond pairs, the shape is square planar (octahedral geometry).

### Conclusion
The molecule that is T-shaped is **ClF3**.