Which of the following does not have a linear structure?

Options

A. `BeCl_(2)`
B. `SO_(2)`
C. `C_(2)H_(2)`
D. `HgCl_(2)`

Answer

To determine which of the given compounds does not have a linear structure, we will analyze the molecular geometry of each compound mentioned: BeCl2, SO2, C2H2, and HgCl2.

### Step 1: Analyze Beryllium Chloride (BeCl2)
- **Hybridization**: Beryllium (Be) has an electronic configuration of 1s² 2s². In BeCl2, Be undergoes sp hybridization to form two equivalent sp hybrid orbitals.
- **Geometry**: The two Cl atoms are bonded to Be, and since there are no lone pairs on Be, the molecular shape is linear.

### Step 2: Analyze Sulfur Dioxide (SO2)
- **Hybridization**: Sulfur (S) has 6 valence electrons. In SO2, the hybridization can be calculated as follows:
\[ \text{Hybridization} = \frac{\text{Valence electrons} + \text{Monovalent atoms} - \text{Cations} + \text{Anions}}{2} \]
Here, S has 6 valence electrons, there are 0 monovalent atoms, 0 cations, and 0 anions:
\[ \text{Hybridization} = \frac{6 + 0 - 0 + 0}{2} = 3 \quad \Rightarrow \quad \text{sp}^2 \]
- **Geometry**: With sp² hybridization, there is one lone pair on sulfur, resulting in an angular (bent) shape, not linear.

### Step 3: Analyze Acetylene (C2H2)
- **Hybridization**: Each carbon in C2H2 is sp hybridized due to the triple bond between the two carbon atoms.
- **Geometry**: The structure is linear because the two sp hybridized carbons are connected by a triple bond, and there are no lone pairs affecting the geometry.

### Step 4: Analyze Mercury(II) Chloride (HgCl2)
- **Hybridization**: Mercury (Hg) has an electronic configuration of [Xe] 4f14 5d10 6s2. In HgCl2, the hybridization is calculated as follows:
\[ \text{Hybridization} = \frac{\text{Valence electrons} + \text{Monovalent atoms} - \text{Cations} + \text{Anions}}{2} \]
Here, Hg has 2 valence electrons, and there are 2 Cl atoms:
\[ \text{Hybridization} = \frac{2 + 2 - 0 + 0}{2} = 2 \quad \Rightarrow \quad \text{sp} \]
- **Geometry**: The structure is linear as well, similar to BeCl2.

### Conclusion
Among the compounds analyzed, **SO2** is the only one that does not have a linear structure; it has an angular structure.

### Final Answer
**SO2 does not have a linear structure.**