` O -N -O` bond angle is maximum in :

Options

A. `N_(2)O`
B. `NO_(2)^(+)`
C. `NO_(2)^(-)`
D. `NO_(3)^(-)`

Explanation

To determine which molecule has the maximum O-N-O bond angle, we will analyze the structures of the given compounds: NO2^+, NO2^-, and NO3^-.

### Step-by-Step Solution:

1. **Identify the Compounds**: We need to analyze the bond angles in the following compounds:
- NO2^+ (Nitronium ion)
- NO2^- (Nitrite ion)
- NO3^- (Nitrate ion)

2. **Analyze NO2^+**:
- Nitrogen (N) has 5 valence electrons.
- In NO2^+, there are 2 oxygen atoms (O) bonded to nitrogen and a positive charge.
- The hybridization of nitrogen can be calculated as follows:
- Valence electrons = 5 (from N) + 0 (from O, since they are divalent) - 1 (due to positive charge) = 4.
- Hybridization = 4/2 = 2 → sp hybridized.
- The geometry is linear, leading to a bond angle of 180°.

3. **Analyze NO2^-**:
- For NO2^-, nitrogen has 5 valence electrons.
- There are 2 oxygen atoms bonded to nitrogen and a negative charge.
- The hybridization is:
- Valence electrons = 5 (from N) + 0 (from O) + 1 (due to negative charge) = 6.
- Hybridization = 6/2 = 3 → sp² hybridized.
- The geometry is trigonal planar, but due to one lone pair, the structure is bent, leading to a bond angle less than 120°.

4. **Analyze NO3^-**:
- For NO3^-, nitrogen has 5 valence electrons.
- There are 3 oxygen atoms bonded to nitrogen and a negative charge.
- The hybridization is:
- Valence electrons = 5 (from N) + 0 (from O) + 1 (due to negative charge) = 6.
- Hybridization = 6/2 = 3 → sp² hybridized.
- The geometry is trigonal planar, leading to a bond angle of approximately 120°.

5. **Compare the Bond Angles**:
- NO2^+: 180° (linear)
- NO2^-: <120° (bent)
- NO3^-: 120° (trigonal planar)

6. **Conclusion**: The maximum O-N-O bond angle is found in NO2^+, which is 180°.

### Final Answer:
The O-N-O bond angle is maximum in NO2^+.