Consider the molecules `CH_(4),NH_(3)` and `H_(2)O` which of the given statement is false ?

Options

A. The H-O-H bond angle in `H_2O` is larger than the H-C-H bond angle in `CH_4`
B. The H-O-H bond angle in `H_2O` is smaller than the H-N-H bond angle in `NH_3`
C. The H-C-H bond angle in `CH_4` is larger than the H-N-H bond angle in `NH_3`
D. The H-C-H bond angle in `CH_4`, the H-N-H bond angle in `NH_3` and the H-O-H bond angle in `H_2O` are all the greater than `90^@`

Explanation

To determine which statement is false regarding the bond angles in the molecules CH₄ (methane), NH₃ (ammonia), and H₂O (water), we will analyze the bond angles of each molecule step by step.

### Step 1: Identify the Molecular Geometry and Bond Angles
1. **CH₄ (Methane)**:
- Molecular Geometry: Tetrahedral
- Bond Angle: 109.5°

2. **NH₃ (Ammonia)**:
- Molecular Geometry: Trigonal pyramidal
- Bond Angle: 107°

3. **H₂O (Water)**:
- Molecular Geometry: Bent or V-shaped
- Bond Angle: 104.5°

### Step 2: Analyze Each Statement
Now, we will evaluate the statements one by one to identify which one is false.

1. **Statement 1**: The HOH bond angle in H₂O is larger than the HCH bond angle in CH₄.
- HOH bond angle in H₂O = 104.5°
- HCH bond angle in CH₄ = 109.5°
- **Conclusion**: This statement is **false** because 104.5° is not larger than 109.5°.

2. **Statement 2**: The HOH bond angle in H₂O is smaller than the HNH bond angle in ammonia.
- HOH bond angle in H₂O = 104.5°
- HNH bond angle in NH₃ = 107°
- **Conclusion**: This statement is **true** because 104.5° is indeed smaller than 107°.

3. **Statement 3**: The HCH bond angle in CH₄ is larger than the HNH bond angle in ammonia.
- HCH bond angle in CH₄ = 109.5°
- HNH bond angle in NH₃ = 107°
- **Conclusion**: This statement is **true** because 109.5° is larger than 107°.

4. **Statement 4**: The HCH bond angle in methane, the HNH bond angle in ammonia, and the HOH bond angle in water are all greater than 90°.
- HCH bond angle in CH₄ = 109.5° (greater than 90°)
- HNH bond angle in NH₃ = 107° (greater than 90°)
- HOH bond angle in H₂O = 104.5° (greater than 90°)
- **Conclusion**: This statement is **true** because all the mentioned bond angles are indeed greater than 90°.

### Final Conclusion
The only false statement among the given options is **Statement 1**.

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