Is the lone pair of electrons on the nitrogen atom in the ammonia molecule stereochemically inactive?

1 Answer
Aug 9, 2017

Answer:

Nope...........

Explanation:

The ammonia molecule has a lone pair of electrons centred on the nitrogen atom, but ALL of the #3xxN-H# bonds are electron-precise #sigma "-bonds"# formed between #dotH# and the nitrogen atom. The remaining 2 electrons on the nitrogen atom comprise a stereochemically active lone pair.....and this lone pair also rationalizes the basicity of the ammonia molecule....

#OH_2 + :NH_3rightleftharpoonsNH_4^+ + HO^(-)#

And to a first approximation ELECTRONIC geometry around nitrogen is tetrahedral. But MOLECULAR geometry is pyramidal.

On the other hand, the nitrogen atom of the ammonium ion is said to be QUATERNIZED #("ammonium"-=NH_4^+)#; that is the nitrogen lone pair forms a so-called #"coordinate covalent bond"# or #"dative"# or #"donative bond"# to the protium ion.......In #"ammonium ion"#, ALL of the #4xxN-H# bonds ARE EQUIVALENT.