JEE Chemistry 2024 Question with Solution

Given: Atomic orbitals $2s$ and $2p$ of a diatomic molecule are combined.

Find: The total number of molecular orbitals formed according to the solution.

In a diatomic molecule, when combining atomic orbitals, both bonding and anti-bonding molecular orbitals are formed.

• From $2s$ orbitals: one bonding $\sigma_{2s}$ and one anti-bonding $\sigma_{2s}^{*}$ molecular orbital are formed.
• From $2p$ orbitals: one bonding $\sigma_{2p}$ and one anti-bonding $\sigma_{2p}^{*}$ orbital are formed, along with two bonding $\pi_{2p}$ and two anti-bonding $\pi_{2p}^{*}$ orbitals.

The solution explicitly counts the anti-bonding orbitals as:

$$1 + 1 + 2 = 4$$

So the extracted conclusion from the solution is that the answer is $4$.

The correct option/value concluded in the solution is $4$. Note that this disagrees with the raw question wording and answer key, which indicate total molecular orbitals and $8$ respectively.