Which one of the following is the correct set with respect to molecule, hybridization and shape ?

Options

A. `BeCl_(2),sp^(2)`, linear
B. `BeCl_(2),sp^(2)`, triangular planar
C. `BCl_(3),sp^(2)`, triangular planar
D. `BCl_(3),sp^(3)`, tetrahedral

Answer

To solve the question regarding the correct set of molecule, hybridization, and shape, we will analyze the options provided. Let's go through the steps systematically.

### Step 1: Analyze BeCl2

1. **Determine the Valence Electrons**:
- Beryllium (Be) has an atomic number of 4, with an electron configuration of 1s² 2s². Therefore, it has 2 valence electrons.
- Each chlorine (Cl) atom has 7 valence electrons, but since we are considering the bonding, we focus on the valence of Be.

2. **Molecule Structure**:
- In BeCl2, beryllium forms bonds with two chlorine atoms. The structure is linear because there are no lone pairs on beryllium.

3. **Calculate Hybridization**:
- The steric number is calculated as follows:
\[ \text{Steric Number} = \text{Number of Valence Electrons} + \text{Number of Monovalent Atoms} = 2 + 2 = 4 \]
- The hybridization corresponding to a steric number of 2 is sp.

4. **Shape**:
- The shape of BeCl2 is linear.

### Step 2: Analyze BCl3

1. **Determine the Valence Electrons**:
- Boron (B) has an atomic number of 5, with an electron configuration of 1s² 2s² 2p¹. Therefore, it has 3 valence electrons.
- Each chlorine (Cl) atom contributes one electron for bonding.

2. **Molecule Structure**:
- In BCl3, boron forms bonds with three chlorine atoms. The structure is trigonal planar because there are no lone pairs on boron.

3. **Calculate Hybridization**:
- The steric number is calculated as follows:
\[ \text{Steric Number} = \text{Number of Valence Electrons} + \text{Number of Monovalent Atoms} = 3 + 3 = 6 \]
- The hybridization corresponding to a steric number of 3 is sp².

4. **Shape**:
- The shape of BCl3 is trigonal planar.

### Step 3: Compare Options

Now we compare the findings with the options provided:

- **Option A**: BeCl2 - sp² - Incorrect (should be sp)
- **Option B**: BCl3 - sp - Incorrect (should be sp²)
- **Option C**: BCl3 - sp² - Correct (matches our findings)
- **Option D**: BeCl2 - sp - Correct (matches our findings)

### Conclusion

The correct set with respect to molecule, hybridization, and shape is:
- **C**: BCl3 - sp² - trigonal planar