Question

PCl₅ exists but NCl₅ does not because ______.

Options

• nitrogen has no vacant d-orbitals.

• NCl₅ is unstable.

• N₂ is inert.

• None of the above.

Answer 1

PCl₅ exists but NCl₅ does not because nitrogen has no vacant d-orbitals.

Explanation:

PCl₅ exists because phosphorus can use its vacant d-orbitals to expand its valence shell and form five covalent bonds. However, nitrogen lacks vacant d-orbitals in its valence shell, so it cannot expand its octet beyond four bonds. Therefore, NCl₅ does not exist, as nitrogen cannot form five bonds like phosphorus can. This is why PCl₅ is stable but NCl₅ is not.