QJEEAdv08Chfb9f: JEE Advanced 2008 Chemistry - Class 12 JEEAdv08Chfb9f Solution: Among the following, the correct statement is :
Among the following, the correct statement is :
Multiple Choice Options
- A Between NH and PH , NH is better electron donor because the lone pair of electrons occupies spherical 's' orbital and is less directional.
- B Between NH and PH , PH is a better electron donor because the lone pair of electrons occupies sp orbital and is more directional.
- C Between NH and PH , NH is a better electron donor because the lone pair of electrons occupies sp orbital and is more directional.
- D Between NH and PH , PH is better electron donor because the lone pair of electrons occupies spherical 's' orbital and is less directional.
Step-by-Step Verified Solution
Both NH and PH have one lone pair of electron on it. The lone pair in case of ammonia occupy sp orbital is directional.
Hence, the lone pair in case of ammonia is easily available and can be easily donated. But for PH 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.
Also the lone pair of electrons in sp orbital has lesser s-character and less attracted by nucleus and available for easy donation than in PH with pure s orbital, the lone pair in which lone pair are more strongly attracted by nucleus. 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 .