`dpi-p pi` bond is present in :

Options

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

Answer

To determine which of the given species contains a D-Pi and P-Pi bond, we need to analyze the bonding in each of the given ions: CO3^2-, PO4^3-, NO3^-, and NO2^-.

### Step-by-Step Solution:

1. **Identify the Valence Electrons:**
- **CO3^2- (Carbonate Ion)**:
- Carbon (C) has 4 valence electrons.
- Each Oxygen (O) has 6 valence electrons.
- Total valence electrons = 4 + (3 × 6) + 2 (for the 2- charge) = 22 electrons.
- **PO4^3- (Phosphate Ion)**:
- Phosphorus (P) has 5 valence electrons.
- Each Oxygen (O) has 6 valence electrons.
- Total valence electrons = 5 + (4 × 6) + 3 (for the 3- charge) = 32 electrons.
- **NO3^- (Nitrate Ion)**:
- Nitrogen (N) has 5 valence electrons.
- Each Oxygen (O) has 6 valence electrons.
- Total valence electrons = 5 + (3 × 6) + 1 (for the -1 charge) = 24 electrons.
- **NO2^- (Nitrite Ion)**:
- Nitrogen (N) has 5 valence electrons.
- Each Oxygen (O) has 6 valence electrons.
- Total valence electrons = 5 + (2 × 6) + 1 (for the -1 charge) = 18 electrons.

2. **Determine the Bonding Types:**
- **CO3^2-**:
- The bonding involves 2p orbitals of Carbon and 2p orbitals of Oxygen, leading to P-Pi bonds.
- **PO4^3-**:
- The bonding involves 3d orbitals of Phosphorus and 2p orbitals of Oxygen, leading to D-Pi and P-Pi bonds.
- **NO3^-**:
- The bonding involves 2p orbitals of Nitrogen and 2p orbitals of Oxygen, leading to P-Pi bonds.
- **NO2^-**:
- The bonding involves 2p orbitals of Nitrogen and 2p orbitals of Oxygen, leading to P-Pi bonds.

3. **Conclusion:**
- Among the given options, only **PO4^3- (Phosphate Ion)** contains both D-Pi and P-Pi bonds due to the involvement of the 3d orbitals of Phosphorus.

### Final Answer:
The species that contains a D-Pi and P-Pi bond is **PO4^3- (Phosphate Ion)**.