`CO_(2)` molecule is not isostructural with :

Options

A. `HgCl_(2)`
B. `SnCl_(2)`
C. `C_(2)H_(2)`
D. `NO_(2)`

Answer

To determine which molecule is not isostructural with CO₂, we need to analyze the structures and hybridizations of the given molecules.

### Step-by-Step Solution:

1. **Identify the Structure of CO₂:**
- CO₂ (carbon dioxide) has a linear structure.
- The carbon atom (C) is in group 14 and has 4 valence electrons.
- Each oxygen atom (O) has 6 valence electrons.
- The molecular structure can be represented as O=C=O.
- The bond angle is 180 degrees.
- The hybridization of carbon in CO₂ is sp (steric number = 2, which is the sum of sigma bonds and lone pairs).

2. **Analyze HgCl₂:**
- HgCl₂ (mercury(II) chloride) also has a linear structure.
- Mercury (Hg) has 2 valence electrons and forms two sigma bonds with chlorine atoms.
- The bond angle is 180 degrees.
- The hybridization is also sp (steric number = 2).
- Conclusion: HgCl₂ is isostructural with CO₂.

3. **Analyze SnCl₂:**
- SnCl₂ (tin(II) chloride) has a different structure.
- Tin (Sn) has 4 valence electrons and forms two sigma bonds with chlorine atoms.
- However, it has one lone pair of electrons.
- The steric number is 3 (2 bond pairs + 1 lone pair), leading to sp² hybridization.
- The structure is angular (bent) due to lone pair-bond pair repulsion.
- Conclusion: SnCl₂ is not isostructural with CO₂.

4. **Analyze C₂H₂:**
- C₂H₂ (acetylene) has a linear structure.
- Each carbon atom forms a triple bond with another carbon and a single bond with hydrogen.
- The hybridization of carbon in C₂H₂ is sp (steric number = 2).
- The bond angle is 180 degrees.
- Conclusion: C₂H₂ is isostructural with CO₂.

5. **Analyze NO₂:**
- NO₂ (nitrogen dioxide) has a bent structure.
- Nitrogen (N) has 5 valence electrons and forms two sigma bonds with oxygen, along with one lone pair.
- The steric number is 3 (2 bond pairs + 1 lone pair), leading to sp² hybridization.
- The bond angle is less than 120 degrees.
- Conclusion: NO₂ is not isostructural with CO₂.

### Final Conclusion:
CO₂ is not isostructural with SnCl₂ and NO₂.