Which of the following has `ppi-dpi` bonding?

Options

A. `NO_3^-`
B. `SO_3^(-2)`
C. `BO_3^(-3)`
D. `CO_3^(-2)`

Answer

To determine which of the given polyatomic ions has Pπ-Dπ bonding, we need to analyze the central atoms of each ion and their ability to utilize d-orbitals in bonding.

### Step-by-Step Solution:

1. **Identify the Central Atoms**:
- For the ions given:
- NO₃⁻ (Nitrate): Central atom is Nitrogen (N).
- SO₃²⁻ (Sulfite): Central atom is Sulfur (S).
- VO₃⁻ (Vanadate): Central atom is Vanadium (V).
- CO₃²⁻ (Carbonate): Central atom is Carbon (C).

2. **Determine the Period of Each Central Atom**:
- Nitrogen (N) is in the 2nd period.
- Sulfur (S) is in the 3rd period.
- Vanadium (V) is in the 4th period.
- Carbon (C) is in the 2nd period.

3. **Check for Vacant d-Orbitals**:
- Elements in the 2nd period (N and C) do not have vacant d-orbitals as they only have s and p orbitals.
- Sulfur (S) in the 3rd period has vacant d-orbitals that can participate in bonding.
- Vanadium (V) in the 4th period also has vacant d-orbitals.

4. **Analyze the Bonding**:
- Pπ-Dπ bonding occurs when a p-orbital from one atom overlaps with a d-orbital from another atom.
- In the case of SO₃²⁻, sulfur can use its vacant d-orbitals to form Pπ-Dπ bonds with oxygen.
- For NO₃⁻, VO₃⁻, and CO₃²⁻, the central atoms (N, C) do not have vacant d-orbitals, thus cannot form Pπ-Dπ bonds.

5. **Conclusion**:
- The only ion that can form Pπ-Dπ bonding is SO₃²⁻ (Sulfite ion).

### Final Answer:
The ion that has Pπ-Dπ bonding is **SO₃²⁻ (Sulfite ion)**.