Question

Ammonia is a good complexing agent. Explain.

Answer 1

1. The lone pair of electrons on the nitrogen atom facilitates the complexation of ammonia with transition metal ions. Thus, ammonia is a good complexing agent as it forms a complex by donating its lone pair of electrons.
   1. \[\ce{\underset{(Blue)}{Cu^2+_{ (aq)}} + 4NH_{3(aq)}->\underset{(Deep blue)}{[Cu(NH3)4]^2+_{( aq)}}}\]
   2. \[\ce{\underset{(White)}{AgCl_{(s)}} + 2NH_{3(aq)}->\underset{(Colourless)}{[Ag(NH3)2]Cl_{( aq)}}}\]
2. This reaction is used for the detection of metal ions such as Cu²⁺ and Ag⁺.