Question

Assertion :R${}_3$P = O exists but R${}_3$N = O does not exist. Reason: P is more electronegative than N.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Both Assertion and Reason are incorrect

Answer 1

The correct option is C Assertion is correct but Reason is incorrect

Nitrogen does not have vacant d-orbitals on its valence shell. Therefore, it cannot extend its covalency to five and dπ−pπ bonding is not possible. As a result, the molecules of R${}_3$N = O does not exist.

However, phosphorus and rest of the members of the group 15 have vacant d-orbitals in the valence shell which can be involved in dπ−pπ bonding. Under the circumstances, R${}_3$P = O molecule can exist.

The electronegativity of $N\left(3.0\right)$ is much higher than $P\left(2.1\right)$.