In which of the following `ppi-dpi` bonding is possible ?

Options

A. `CO_(3)^(2-)`
B. `PO_(4)^(3-)`
C. `NO_(3)^(-)`
D. `NO_(2)^(-)`

Explanation

To determine in which of the following compounds Pπ-Dπ bonding is possible, we need to analyze the central atom of each compound and its electronic configuration. Pπ-Dπ bonding occurs when there is a suitable p orbital from one atom that can overlap with a d orbital from another atom.

Let's analyze the options one by one:

### Step 1: Analyze Carbonate (CO₃²⁻)
- **Central Atom**: Carbon (C)
- **Atomic Number**: 6
- **Electronic Configuration**: 1s² 2s² 2p²
- **Analysis**: Carbon has no d orbitals available (the highest principal quantum number is n=2). Therefore, Pπ-Dπ bonding is not possible in carbonate.

### Step 2: Analyze Phosphate (PO₄³⁻)
- **Central Atom**: Phosphorus (P)
- **Atomic Number**: 15
- **Electronic Configuration**: 1s² 2s² 2p⁶ 3s² 3p³
- **Analysis**: Phosphorus has d orbitals available in the third shell (n=3). Thus, it can utilize these d orbitals to form Pπ-Dπ bonding. Therefore, Pπ-Dπ bonding is possible in phosphate.

### Step 3: Analyze Nitrite (NO₂⁻)
- **Central Atom**: Nitrogen (N)
- **Atomic Number**: 7
- **Electronic Configuration**: 1s² 2s² 2p³
- **Analysis**: Nitrogen has no d orbitals available (the highest principal quantum number is n=2). Therefore, Pπ-Dπ bonding is not possible in nitrite.

### Step 4: Analyze Nitrate (NO₃⁻)
- **Central Atom**: Nitrogen (N)
- **Atomic Number**: 7
- **Electronic Configuration**: 1s² 2s² 2p³
- **Analysis**: Similar to nitrite, nitrogen has no d orbitals available. Therefore, Pπ-Dπ bonding is not possible in nitrate.

### Conclusion
Based on the analysis, the only compound where Pπ-Dπ bonding is possible is **Phosphate (PO₄³⁻)**.

### Final Answer:
**Phosphate (PO₄³⁻)** is the correct answer where Pπ-Dπ bonding is possible.

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