Question

$PCl_5$ is well known but $NCl_5$ is not. Because.

• A. nitrogen is less reactive than phosphorous.
• B. nitrogen doesn't have d-orbitals in its valence shell.
• C. catenation tendency is weaker in nitrogen than phosphorous.
• D. size of phosphorous is larger than nitrogen.

Answer 1

Answer: (B)

$PCl _{5}$ forms five bonds by using the d-orbitals to "expand the octet". But $NCl _{5}$ does not exist because there are no $d -$ orbitals in the valence shell ( $2^{\text {nd }}$ shell). Therefore there is no way to expand the octet.