Which set of oxide of nitrogen is paramagnetic in monomeric state?

Options

A. No, `N_(2)O`
B. `NO_(2),N_(2)O`
C. `NO,NO_(2)`
D. `N_(2)O,NO,NO_(2)`

Answer

To determine which set of nitrogen oxides is paramagnetic in their monomeric state, we need to analyze the valence electrons of each compound and check for unpaired electrons.

### Step-by-Step Solution:

1. **Understand Paramagnetism**:
- Paramagnetic substances have unpaired electrons in their molecular orbitals. If a molecule has an odd number of valence electrons, it is likely to be paramagnetic.

2. **Identify the Compounds**:
- The compounds to analyze are:
- NO (Nitric oxide)
- N2O (Dinitrogen monoxide)
- NO2 (Nitrogen dioxide)

3. **Calculate Valence Electrons**:
- **For NO**:
- Nitrogen (N) has 5 valence electrons and Oxygen (O) has 6 valence electrons.
- Total = 5 (N) + 6 (O) = 11 electrons (odd number).
- Since there is an odd number of electrons, NO is **paramagnetic**.

- **For N2O**:
- There are 2 Nitrogen atoms and 1 Oxygen atom.
- Total = 2 * 5 (N) + 6 (O) = 10 + 6 = 16 electrons (even number).
- Since there is an even number of electrons, N2O is **diamagnetic**.

- **For NO2**:
- There is 1 Nitrogen atom and 2 Oxygen atoms.
- Total = 5 (N) + 2 * 6 (O) = 5 + 12 = 17 electrons (odd number).
- Since there is an odd number of electrons, NO2 is **paramagnetic**.

4. **Summarize the Findings**:
- NO: Paramagnetic (11 electrons)
- N2O: Diamagnetic (16 electrons)
- NO2: Paramagnetic (17 electrons)

5. **Evaluate the Options**:
- Option 1: NO, N2O → NO is paramagnetic, N2O is diamagnetic (not correct).
- Option 2: NO2, N2O → NO2 is paramagnetic, N2O is diamagnetic (not correct).
- Option 3: NO, NO2 → Both NO and NO2 are paramagnetic (correct).
- Option 4: N2O, NO, NO2 → N2O is diamagnetic, while NO and NO2 are paramagnetic (not correct).

6. **Conclusion**:
- The correct answer is **Option 3: NO and NO2**, as both are paramagnetic in their monomeric states.