Which one of the following molecules contains no `pi` - bond ?

Options

A. `NO_2`
B. `CO_2`
C. `H_2O`
D. `SbCl_3`

Answer

To determine which of the given molecules contains no pi bond, we need to analyze the bonding in each molecule. Let's go through the options step by step.

### Step 1: Analyze NO2 (Nitrogen Dioxide)
- **Structure**: Nitrogen (N) is the central atom with 5 valence electrons. It forms a double bond with each oxygen atom.
- **Bonding**: In NO2, there is one double bond (N=O), which consists of one sigma bond and one pi bond.
- **Conclusion**: NO2 contains pi bonds.

### Step 2: Analyze CO2 (Carbon Dioxide)
- **Structure**: Carbon (C) is the central atom with 4 valence electrons. It forms double bonds with each oxygen atom.
- **Bonding**: In CO2, there are two double bonds (O=C=O), each consisting of one sigma bond and one pi bond.
- **Conclusion**: CO2 contains pi bonds.

### Step 3: Analyze H2O (Water)
- **Structure**: Oxygen (O) is the central atom with 6 valence electrons. It forms single bonds with two hydrogen atoms.
- **Bonding**: In H2O, there are only single bonds (H-O-H), which consist of sigma bonds only. There are also two lone pairs on oxygen.
- **Conclusion**: H2O contains no pi bonds.

### Step 4: Analyze SbCl3 (Antimony Trichloride)
- **Structure**: Antimony (Sb) is the central atom with 5 valence electrons. It forms single bonds with three chlorine atoms.
- **Bonding**: In SbCl3, there are three single bonds (Sb-Cl), which consist of sigma bonds only. There is also one lone pair on antimony.
- **Conclusion**: SbCl3 contains no pi bonds.

### Final Conclusion
From the analysis:
- NO2 contains pi bonds.
- CO2 contains pi bonds.
- H2O contains no pi bonds.
- SbCl3 contains no pi bonds.

Thus, the molecules that contain no pi bond are **H2O and SbCl3**.

### Answer: H2O and SbCl3 contain no pi bonds.

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