JEE Chemistry 2024 Question with Solution

Given: We need the sum of bond orders of $\mathrm{CO}$ and $\mathrm{NO}^+$.

Find: $\text{Bond order of CO} + \text{Bond order of NO}^+$.

Using molecular orbital theory, bond order is

For $\mathrm{CO}$, the bond order is stated as

For $\mathrm{NO}^+$, it has the same effective valence electron count and similar molecular orbital filling, so its bond order is also

Therefore, the required sum is

So, the sum of the bond orders of $\mathrm{CO}$ and $\mathrm{NO}^+$ is $6$.

The answer key shows $5$, but the solution consistently concludes $6$; hence the answer is taken as $6$.

The solution also gives the equivalent structural interpretation: $\mathrm{CO}$ has bond order $3$ and $\mathrm{NO}^+$ also has bond order $3$, so the total is $6$.

Given: $\mathrm{CO}$ and $\mathrm{NO}^+$.

Find: Sum of their bond orders.

Both species are isoelectronic and are described in the solution as having triple-bond character. Therefore,

Hence,

Therefore, the required numerical value is $6$.