The state of hybridisation for the transition state of hydrolysis mechanism of `BCI_(3)` and `SF_(4)` are respectively

Options

A. `sp^(2),sp^(3)d`
B. `sp^(3),sp^(3)`
C. `sp^(3),sp^(3)`
D. `sp^(3),sp^(3)d^(2)`

Answer

To determine the state of hybridization for the transition state of the hydrolysis mechanism of BCl3 and SF4, we can follow these steps:

### Step 1: Determine the Hybridization of BCl3
1. **Identify the Valence Electrons**:
- Boron (B) has 3 valence electrons.
- Each Chlorine (Cl) has 7 valence electrons. Since there are 3 Cl atoms, the total from Cl is \(3 \times 7 = 21\).
- Total valence electrons = \(3 + 21 = 24\).

2. **Calculate the Number of Electron Pairs**:
- Divide the total valence electrons by 2 to find the number of electron pairs: \( \frac{24}{2} = 12\) pairs.
- This means we have 3 bond pairs (from BCl3) and 0 lone pairs.

3. **Determine Hybridization**:
- With 3 bond pairs and 0 lone pairs, the hybridization of BCl3 is **sp²**.

4. **Transition State During Hydrolysis**:
- When BCl3 undergoes hydrolysis, it interacts with water (H2O), resulting in a transition state where boron is bonded to 4 species (3 Cl and 1 H2O).
- This changes the hybridization to **sp³**.

### Step 2: Determine the Hybridization of SF4
1. **Identify the Valence Electrons**:
- Sulfur (S) has 6 valence electrons.
- Each Fluorine (F) has 7 valence electrons. Since there are 4 F atoms, the total from F is \(4 \times 7 = 28\).
- Total valence electrons = \(6 + 28 = 34\).

2. **Calculate the Number of Electron Pairs**:
- Divide the total valence electrons by 2: \( \frac{34}{2} = 17\) pairs.
- This means we have 4 bond pairs and 1 lone pair (since \(34 - 32 = 2\) electrons left, which forms 1 lone pair).

3. **Determine Hybridization**:
- With 4 bond pairs and 1 lone pair, the hybridization of SF4 is **sp³d**.

4. **Transition State During Hydrolysis**:
- When SF4 undergoes hydrolysis, it will also interact with water, resulting in a transition state where sulfur is bonded to 6 species (4 F and 2 H from water).
- This changes the hybridization to **sp³d²**.

### Conclusion
- The hybridization states for the transition states of hydrolysis are:
- For BCl3: **sp³**
- For SF4: **sp³d²**

### Final Answer
The state of hybridization for the transition state of hydrolysis mechanism of BCl3 and SF4 are respectively **sp³** and **sp³d²**.

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