Given the species : `N_2, CO, CN^–` and `NO^+`. Which of the following statements are true for these ?

Options

A. All species are paramagnetic
B. The species are isoelectronic
C. All the species have dipole moment
D. All the species are linear

Answer

To determine the properties of the given species \(N_2\), \(CO\), \(CN^-\), and \(NO^+\), we will analyze each species step by step.

### Step 1: Count the total number of electrons for each species

1. **For \(N_2\)**:
- Each nitrogen atom has 7 electrons.
- Total for \(N_2 = 7 + 7 = 14\) electrons.

2. **For \(CO\)**:
- Carbon has 6 electrons and oxygen has 8 electrons.
- Total for \(CO = 6 + 8 = 14\) electrons.

3. **For \(CN^-\)**:
- Carbon has 6 electrons, nitrogen has 7 electrons, and the negative charge adds 1 more electron.
- Total for \(CN^- = 6 + 7 + 1 = 14\) electrons.

4. **For \(NO^+\)**:
- Nitrogen has 7 electrons, oxygen has 8 electrons, and the positive charge subtracts 1 electron.
- Total for \(NO^+ = 7 + 8 - 1 = 14\) electrons.

### Step 2: Determine the electron configuration for each species

1. **For \(N_2\)**:
- Configuration: \( \sigma_{1s}^2 \sigma_{1s}^* \sigma_{2s}^2 \sigma_{2s}^* \sigma_{2p_z}^2 \pi_{2p_x}^2 \pi_{2p_y}^2 \)
- All electrons are paired.

2. **For \(CO\)**:
- Configuration: \( \sigma_{1s}^2 \sigma_{1s}^* \sigma_{2s}^2 \sigma_{2s}^* \sigma_{2p_z}^2 \pi_{2p_x}^2 \pi_{2p_y}^2 \)
- All electrons are paired.

3. **For \(CN^-\)**:
- Configuration: \( \sigma_{1s}^2 \sigma_{1s}^* \sigma_{2s}^2 \sigma_{2s}^* \sigma_{2p_z}^2 \pi_{2p_x}^2 \pi_{2p_y}^2 \)
- All electrons are paired.

4. **For \(NO^+\)**:
- Configuration: \( \sigma_{1s}^2 \sigma_{1s}^* \sigma_{2s}^2 \sigma_{2s}^* \sigma_{2p_z}^2 \pi_{2p_x}^2 \pi_{2p_y}^2 \)
- One electron is removed, so it has paired electrons.

### Step 3: Analyze magnetic properties

- **Paramagnetic**: Species with unpaired electrons.
- **Diamagnetic**: Species with all paired electrons.

From the configurations:
- \(N_2\), \(CO\), \(CN^-\), and \(NO^+\) are all **diamagnetic** since they have no unpaired electrons.

### Step 4: Check for isoelectronic species

- Isoelectronic species have the same number of electrons.
- All four species have 14 electrons, thus they are **isoelectronic**.

### Step 5: Determine dipole moments

- **\(N_2\)**: Non-polar (no electronegativity difference).
- **\(CO\)**: Polar (electronegativity difference exists).
- **\(CN^-\)**: Polar (electronegativity difference exists).
- **\(NO^+\)**: Polar (electronegativity difference exists).

### Conclusion

1. All species are **diamagnetic** (false statement if claimed paramagnetic).
2. All species are **isoelectronic** (true statement).
3. Not all species have a dipole moment (false statement).

### Final Statements

- True statements:
- They are isoelectronic.
- False statements:
- They are all paramagnetic.
- Not all have dipole moments.