The species in which the N-atom is in a state of sp hybridisation is

Options

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

Answer

To determine the species in which the nitrogen atom is in a state of sp hybridization, we will follow these steps:

### Step 1: Understand Hybridization and Steric Number
Hybridization is a concept used to describe the mixing of atomic orbitals to form new hybrid orbitals. The type of hybridization can be determined by calculating the steric number (SN), which is given by the formula:
\[ \text{Steric Number} = \text{Number of Lone Pairs} + \text{Number of Bond Pairs} \]

### Step 2: Identify the Valence Electrons of Nitrogen
Nitrogen has 5 valence electrons, which can be represented as follows:
- Electronic configuration: \( 1s^2 2s^2 2p^3 \)
- Therefore, nitrogen has 2 electrons in the 2s orbital and 3 electrons in the 2p orbitals.

### Step 3: Analyze Each Species
We will analyze the given species to find the one with sp hybridization (steric number = 2).

1. **NO2⁻ (Nitrite Ion)**
- Valence electrons: 5 (from N) + 1 (extra from -1 charge) = 6
- Structure: N forms 2 sigma bonds with O (double bond with one O) and has 1 lone pair.
- Steric Number: 1 (lone pair) + 2 (bond pairs) = 3 (sp² hybridization).

2. **NO3⁻ (Nitrate Ion)**
- Valence electrons: 5 (from N) + 1 (extra from -1 charge) = 6
- Structure: N forms 3 sigma bonds with O (double bond with one O) and has 0 lone pairs.
- Steric Number: 0 (lone pairs) + 3 (bond pairs) = 3 (sp² hybridization).

3. **NO2 (Nitrogen Dioxide)**
- Valence electrons: 5 (from N) = 5
- Structure: N forms 2 sigma bonds with O (one double bond) and has 1 lone pair.
- Steric Number: 1 (lone pair) + 2 (bond pairs) = 3 (sp² hybridization).

4. **NO2⁺ (Nitronium Ion)**
- Valence electrons: 5 (from N) - 1 (removed due to +1 charge) = 4
- Structure: N forms 2 sigma bonds with O (both double bonds) and has 0 lone pairs.
- Steric Number: 0 (lone pairs) + 2 (bond pairs) = 2 (sp hybridization).

### Step 4: Conclusion
From the analysis, we see that the only species where nitrogen is in the state of sp hybridization is **NO2⁺** (Nitronium Ion).

### Final Answer
The species in which the N-atom is in a state of sp hybridization is **NO2⁺**.

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