The nitrogen atom of NH_(3) acts as a donor during the formation of a co-ordinate covalent bond while the central nitrogen atom in NO_(2) cannot act as a donor. Explain.

The nitrogen atom of NH_(3) acts as a donor during the formation of a

1.	The nitrogen atom of NH_(3) acts as a donor during the formation of a co-ordinate covalent bond while the central nitrogen atom in NO_(2) cannot act as a donor. Explain.
Answer» Solution :The central nitrogen atom of ammonia has lone pair of ELECTRONS on it that can be donated to form co-ordinate COVALENT BOND, which is obvious from the nature of BONDING present in `NH_(3)`. Thus, the central N atom of `NH_(3)` acts as a donor. The central 'N' atom of `NO_(2)` doesn't participate in co-ordinate covalent bond formation due to the lack of lone electron pair on nitrogen. The central 'N' participates in co-ordinate covalent bond formation with oxygen during the formation of `NO_(2)` and thus it cannot further ACT as donor and forms co-ordinate covalent bond with other species that is obvious from the nature of bonding present in `NO_(2)`.