Which of the following pair consists of only paramagetic species?

Options

A. `H_(2), O_(2)^(+)`
B. `N_(2), O_(2)`
C. CO, `N_(2)`
D. `H_(2)^(+)` , `O_(2)^(-)`

Answer

To determine which of the following pairs consists of only paramagnetic species, we need to analyze the electronic configurations of the given molecules and ions to identify the presence of unpaired electrons. A species is considered paramagnetic if it has one or more unpaired electrons.

### Step-by-Step Solution:

1. **Identify the Species**: We need to analyze the electronic configurations of the following species:
- H2
- H2+
- O2
- O2+
- O2-
- N2
- CO

2. **Analyze H2**:
- H2 has 2 electrons, and its electronic configuration is σ1s².
- Both electrons are paired, making H2 **diamagnetic**.

3. **Analyze H2+**:
- H2+ has 1 electron (since one electron is removed from H2).
- Its electronic configuration is σ1s¹.
- There is 1 unpaired electron, making H2+ **paramagnetic**.

4. **Analyze O2**:
- O2 has 16 electrons, and its electronic configuration is:
- σ1s² σ*1s² σ2s² σ*2s² σ2p² (2 electrons in σ2p)
- π2p² (2 electrons in π2p)
- O2 has 2 unpaired electrons, making it **paramagnetic**.

5. **Analyze O2+**:
- O2+ has 15 electrons (one electron removed from O2).
- Its electronic configuration will still have 1 unpaired electron, making O2+ **paramagnetic**.

6. **Analyze O2-**:
- O2- has 17 electrons (one extra electron added to O2).
- It will still have 1 unpaired electron, making O2- **paramagnetic**.

7. **Analyze N2**:
- N2 has 14 electrons, and its electronic configuration is:
- σ1s² σ*1s² σ2s² σ*2s² π2p² (2 electrons in π2p)
- σ2p²
- All electrons are paired, making N2 **diamagnetic**.

8. **Analyze CO**:
- CO has 14 electrons, and its electronic configuration is:
- σ1s² σ*1s² σ2s² σ*2s² σ2p² (2 electrons in σ2p)
- π2p²
- All electrons are paired, making CO **diamagnetic**.

9. **Determine the Pair with Only Paramagnetic Species**:
- From the analysis:
- H2: diamagnetic
- H2+: paramagnetic
- O2: paramagnetic
- O2+: paramagnetic
- O2-: paramagnetic
- N2: diamagnetic
- CO: diamagnetic
- The only pair that consists of only paramagnetic species is **O2+ and O2-**.

### Conclusion:
The pair that consists of only paramagnetic species is **O2+ and O2-**.