Question

Assertion :Molecular nitrogen is less reactive than molecular oxygen. Reason: The bond length of $N_2$ is shorter than that of oxygen.

• A. If both assertion and reason are true and the reason is a correct explanation of the assertion
• B. If both assertion and reason are true but reason is not a correct explanation of the assertion
• C. If the assertion is true but reason is false
• D. If both the assertion and reason are false

Answer 1

The correct option is B If both assertion and reason are true but reason is not a correct explanation of the assertion

The electronic configuration of nitrogen is: $\left[He\right]{2s}^2{2p}_x^1{2p}_y^1{2p}_z^1$

The electronic configuration of oxygen is: $\left[He\right]{2s}^2{2p}_x^2{2p}_y^1{2p}_z^1$

Both have valence electrons electrons in 2p orbitals.

But oxygen has partially filled 2p orbitals which is less stable due to spin pair electronic repulsion between 2 electrons whereas nitrogen has half filled or singly filled orbitals having nospin pair electronic repulsion.

Hence, nitrogen is more stable.