Which of the following has maximum bond angle ?
`H_(2)O,NH_(3),CO_(2),CH_(4)`
Give suitable explanation for your answer.

Answer

To determine which of the given molecules has the maximum bond angle, we will analyze the molecular geometry and bond angles of each compound: H₂O (water), NH₃ (ammonia), CO₂ (carbon dioxide), and CH₄ (methane).

### Step-by-Step Solution:

1. **Identify the Molecular Geometry:**
- **H₂O (Water):** Water has a bent molecular geometry due to the presence of two lone pairs on the oxygen atom. The bond angle is approximately 104.5°.
- **NH₃ (Ammonia):** Ammonia has a trigonal pyramidal shape due to one lone pair on the nitrogen atom. The bond angle is approximately 107°.
- **CO₂ (Carbon Dioxide):** Carbon dioxide has a linear structure because it has no lone pairs on the central carbon atom. The bond angle is 180°.
- **CH₄ (Methane):** Methane has a tetrahedral geometry with no lone pairs on the central carbon atom. The bond angle is approximately 109.5°.

2. **Compare the Bond Angles:**
- H₂O: 104.5°
- NH₃: 107°
- CO₂: 180°
- CH₄: 109.5°

3. **Determine the Maximum Bond Angle:**
- Among the bond angles calculated, CO₂ has the highest bond angle of 180°.

### Conclusion:
The molecule with the maximum bond angle is **CO₂ (carbon dioxide)**, which has a linear structure resulting in a bond angle of 180°.