Which of the following pairs is isostractural (i.e having the same shape and hybridization ?

Options

A. `[BCl_(3)and BrCl_(3)]`
B. `[NH_(3)and NO_(3)^(-)]`
C. `[NF_(3)and BF_(3)]`
D. `[BF_(4)^(-)and NH_(4)^(+)]`

Explanation

To determine which of the given pairs is isostructural (having the same shape and hybridization), we will analyze each pair one by one.

### Step 1: Analyze BCl3 and BrCl3
- **BCl3 (Boron Trichloride)**:
- Hybridization: sp²
- Shape: Trigonal planar
- **BrCl3 (Bromine Trichloride)**:
- Hybridization: sp³d
- Shape: T-shaped

**Conclusion**: BCl3 and BrCl3 are not isostructural.

### Step 2: Analyze NH3 and NO3⁻
- **NH3 (Ammonia)**:
- Hybridization: sp³
- Shape: Pyramidal
- **NO3⁻ (Nitrate Ion)**:
- Hybridization: sp²
- Shape: Trigonal planar

**Conclusion**: NH3 and NO3⁻ are not isostructural.

### Step 3: Analyze NF3 and BF3
- **NF3 (Nitrogen Trifluoride)**:
- Hybridization: sp³
- Shape: Pyramidal
- **BF3 (Boron Trifluoride)**:
- Hybridization: sp²
- Shape: Trigonal planar

**Conclusion**: NF3 and BF3 are not isostructural.

### Step 4: Analyze BF4⁻ and NH4⁺
- **BF4⁻ (Tetrafluoroborate Ion)**:
- Hybridization: sp³
- Shape: Tetrahedral
- **NH4⁺ (Ammonium Ion)**:
- Hybridization: sp³
- Shape: Tetrahedral

**Conclusion**: BF4⁻ and NH4⁺ are isostructural.

### Final Answer:
The pair that is isostructural is **BF4⁻ and NH4⁺**.

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