Which one of the following pairs of chemical species contains the ions having same hybridisation of the central atoms?

Options

A. `NO_(2)^(-) and NH_(2)^(-)`
B. `NO_(2)^(-) and NO_(3)^(-)`
C. `NH_(4)^(+) and NO_(3)^(-)`
D. `SCN^(-) and NH_(2)^(-)`

Answer

To determine which pair of chemical species contains ions with the same hybridization of their central atoms, we will analyze the hybridization of each species mentioned in the question.

### Step-by-Step Solution:

1. **Identify the Chemical Species:**
We have the following pairs of ions:
- Pair 1: NO2⁻ and NH2⁻
- Pair 2: NO2⁻ and NO3⁻
- Pair 3: NH4⁺ and NO3⁻
- Pair 4: SCN⁻ and NH2⁻

2. **Calculate Hybridization for Each Ion:**
The formula for hybridization is:
\[ \text{Hybridization} = \frac{\text{Valence Electrons of Central Atom} + \text{Number of Monovalent Atoms} + \text{Charge}}{2} \]

**Pair 1: NO2⁻ and NH2⁻**
- **NO2⁻:**
- Valence electrons of N = 5
- Number of O atoms (monovalent) = 2
- Charge = -1
\[ \text{Hybridization} = \frac{5 + 2 + 1}{2} = \frac{8}{2} = 4 \quad \text{(sp³)} \]
- **NH2⁻:**
- Valence electrons of N = 5
- Number of H atoms (monovalent) = 2
- Charge = -1
\[ \text{Hybridization} = \frac{5 + 2 + 1}{2} = \frac{8}{2} = 4 \quad \text{(sp³)} \]

**Pair 2: NO2⁻ and NO3⁻**
- **NO2⁻:** (calculated above)
- Hybridization = sp³
- **NO3⁻:**
- Valence electrons of N = 5
- Number of O atoms (monovalent) = 3
- Charge = -1
\[ \text{Hybridization} = \frac{5 + 3 + 1}{2} = \frac{9}{2} = 4.5 \quad \text{(sp²)} \]

**Pair 3: NH4⁺ and NO3⁻**
- **NH4⁺:**
- Valence electrons of N = 5
- Number of H atoms (monovalent) = 4
- Charge = +1
\[ \text{Hybridization} = \frac{5 + 4 - 1}{2} = \frac{8}{2} = 4 \quad \text{(sp³)} \]
- **NO3⁻:** (calculated above)
- Hybridization = sp²

**Pair 4: SCN⁻ and NH2⁻**
- **SCN⁻:**
- Valence electrons of C = 4
- Number of S atoms = 1
- Number of N atoms = 1
- Charge = -1
\[ \text{Hybridization} = \frac{4 + 1 + 1}{2} = \frac{6}{2} = 3 \quad \text{(sp²)} \]
- **NH2⁻:** (calculated above)
- Hybridization = sp³

3. **Compare Hybridizations:**
- Pair 1: NO2⁻ (sp³) and NH2⁻ (sp³) - Same hybridization
- Pair 2: NO2⁻ (sp³) and NO3⁻ (sp²) - Different hybridization
- Pair 3: NH4⁺ (sp³) and NO3⁻ (sp²) - Different hybridization
- Pair 4: SCN⁻ (sp²) and NH2⁻ (sp³) - Different hybridization

### Conclusion:
The pair of chemical species that contains ions with the same hybridization of the central atoms is **NO2⁻ and NH2⁻**, both having sp³ hybridization.