Differences between ammonia (NH3) and phosphine ( PH3)

March 24, 2018

S.N	NH₃	PH₃
1.	It is lighter than air.	It is heavier than air.
2.	It is not poisonous.	It is highly poisonous.
3.	It forms H-bonding.	It does not form H-bonding.
4.	It is highly soluble in water.	It is sparingly soluble in water.
5.	Its aqueous solution is alkaline.	Its aqueous solution is neutral.
6.	It forms NH₄OH i.e. stable	It forms PH₄OH i.e. unstable.
7.	It forms complexes.	It does not form complexes.
8.	Its bond angle is 107º.	Its bond angle is 93º.
9.	It is called ammonia (azane).	It is called phosphine (phosphane).
10.	It is a compound of nitrogen.	It is a compound of phosphorous.
11.	It has higher boiling point.	It has less boiling point.
12.	2Na + 2NH₃ → 2NaNH₂ + H₂↑	6Na + 2PH₃ → 2Na₃P + 3H₂
13.	It burns in excess of air or oxygen giving nitrogen and water. 4NH₃+ 3O₂ → 2N₂ + 6H₂O	It burns in oxygen yielding phosphorous pentoxide and water. 2PH₃ + 4O₂ → P₂O₅ + 3H₂O
14.	It forms stable salts known as ammonium salts.	It forms unstable salts known as phosphonium salt.
15.	It precipitates out metals from their aqueous salt solution as metallic hydrides. Image source: studious	It precipitates out metals from their salt solution as metallic phosphides. Image source: chemistryworld