Maximum bond angle at nitrogen is present in which of the following ?

Options

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

Explanation

To determine the maximum bond angle at nitrogen in the given options (NO2, NO2-, NO2+, and NO3-), we will follow a systematic approach to analyze the hybridization and geometry of each species.

### Step-by-Step Solution:

1. **Identify Valence Electrons for Each Species:**
- **NO2:**
- Nitrogen (N) has 5 valence electrons.
- Each Oxygen (O) has 6 valence electrons, and there are 2 O atoms.
- Total = 5 + (6 × 2) = 17 valence electrons.
- **NO2-:**
- Same as NO2 but with an additional electron due to the negative charge.
- Total = 17 + 1 = 18 valence electrons.
- **NO2+:**
- Same as NO2 but with one less electron due to the positive charge.
- Total = 17 - 1 = 16 valence electrons.
- **NO3-:**
- Nitrogen has 5 valence electrons and there are 3 O atoms.
- Total = 5 + (6 × 3) + 1 (extra electron due to negative charge) = 24 valence electrons.

2. **Calculate Bond Pairs and Lone Pairs:**
- Use the formula:
- Total valence electrons / 8 = number of bond pairs.
- Remainder / 2 = number of lone pairs.
- **NO2:**
- 17 / 8 = 2 bond pairs (16) and 1 remainder (1).
- 1 / 2 = 0.5 lone pairs (0).
- **NO2-:**
- 18 / 8 = 2 bond pairs (16) and 2 remainder (2).
- 2 / 2 = 1 lone pair.
- **NO2+:**
- 16 / 8 = 2 bond pairs (16) and 0 remainder (0).
- 0 / 2 = 0 lone pairs.
- **NO3-:**
- 24 / 8 = 3 bond pairs (24) and 0 remainder (0).
- 0 / 2 = 0 lone pairs.

3. **Determine Hybridization and Geometry:**
- **NO2:**
- Hybridization: sp (2 bond pairs, 1 lone pair).
- Geometry: Bent, bond angle < 120°.
- **NO2-:**
- Hybridization: sp2 (2 bond pairs, 1 lone pair).
- Geometry: Bent, bond angle ≈ 115°.
- **NO2+:**
- Hybridization: sp (2 bond pairs, 0 lone pairs).
- Geometry: Linear, bond angle = 180°.
- **NO3-:**
- Hybridization: sp2 (3 bond pairs, 0 lone pairs).
- Geometry: Trigonal planar, bond angle = 120°.

4. **Conclusion:**
- The maximum bond angle at nitrogen is found in **NO2+**, which has a bond angle of **180°**.

### Final Answer:
The maximum bond angle at nitrogen is present in **NO2+**.

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