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

Options

A. `CO_(2)`
B. `H_(2)O`
C. `SO_(2)`
D. `NO_(2)`

Explanation

To determine which molecule contains no pi bonds, we need to analyze the bonding structure of the given molecules. Let's consider the following common molecules: CO2, H2O, SO2, and NH3.

### Step-by-Step Solution:

1. **Identify the Molecules**: The molecules to analyze are CO2 (carbon dioxide), H2O (water), SO2 (sulfur dioxide), and NH3 (ammonia).

2. **Analyze CO2**:
- Carbon (C) has a valence of 4 and forms two double bonds with oxygen (O).
- Each double bond consists of one sigma bond and one pi bond.
- Therefore, CO2 has **2 pi bonds**.

3. **Analyze H2O**:
- Oxygen (O) has a valence of 6 and forms two single bonds with hydrogen (H).
- Each single bond consists of one sigma bond and no pi bonds.
- Therefore, H2O has **0 pi bonds**.

4. **Analyze SO2**:
- Sulfur (S) has a valence of 6 and forms two double bonds with oxygen (O).
- Each double bond consists of one sigma bond and one pi bond.
- Therefore, SO2 has **2 pi bonds**.

5. **Analyze NH3**:
- Nitrogen (N) has a valence of 5 and forms three single bonds with hydrogen (H).
- Each single bond consists of one sigma bond and no pi bonds.
- Therefore, NH3 has **0 pi bonds**.

6. **Conclusion**:
- Among the molecules analyzed, both H2O and NH3 contain no pi bonds. However, if we are to choose one, H2O is often the most recognized as having no pi bonds.

### Final Answer:
The molecule that contains no pi bonds is **H2O (water)**.

---