Question

if a lone pair is in more directional orbital it can be donated easily,on the contrary if it is present in a less directional orbital it can not be donated. *How the nature of orbital of being directional or non directional affects easy donation of lone pair?*​

Answer 1

Answer:

Both NH

3

and PH

3

have one lone pair of electron on it. The lone pair in case of Ammonia occupy higher energy orbital sp

3

, which has p−character more in it than pure s-orbital and is more directional. Hence the lone pair in case of Ammonia is easily available and can be easily donated.

But for PH

3

the lone pair of electrons occupy spherical s-orbital which is less directional and thus its lone pair is not easily available neither it can be donated easily.

As we go down a group, the p-character in bond pair increases and the s-character in lone pair increases.

Thus ammonia is a better base than PH

3

.

Hence, the correct option is C