Question

Which one of the following homo-diatomic molecule is paramagnetic?

विकल्प

• O₂

• N₂

• C₂

• F₂

Answer 1

O₂ 

Explanation:

For O₂ molecule M.O configuration. (16 electrons) 

\[\ce{σ 1s^2 σ^∗ 1s^2 σ 2s^2 σ^∗ 2s^2 σ 2p^{2}_z π2p^{2}_x = π2p^{2}_y π^∗ 2P^{1}_y π^∗ 2P_z}\]

For N₂ molecule (12 electrons)

\[\ce{σ 1s^2 σ^∗ ls^2 σ 2s^2 σ^∗ 2s^2 π2p^{2}_x = π2p^{2}_y}\]

For F₂ molecule (18 electrons)

\[\ce{σ 1s^2 σ^∗ ls^2 σ 2s^2 σ^∗ 2s^2 σ2p^{2}_r  π2p^{2}_x = π2p^{2}_y π^∗ 2p^{2}_x = π^∗ 2p^{2}_y σ^* 2p_z}\]

O₂ molecule is paramagnetic with 2 unpaired electrons in π^*2p_x and π^*2p_y orbitals.