for the complex ion equilibria between AgCl and NH3, why does NH3 replace Cl- and how do we know that we have to add 2 infront of NH3? Is the product a salt compound?
Ag + 2NH3= Ag(NH3)2+
Answered above by Dr Jim
In the complex ion equilibria between AgCl and NH3, NH3 replaces Cl- because NH3 is a stronger ligand (a molecule or ion that can bind to a metal ion) than Cl-. When NH3 is added to a solution containing AgCl, it can displace Cl- from the Ag+ ion to form the complex ion Ag(NH3)2+.
The reason why we add 2 in front of NH3 is because the Ag(NH3)2+ complex has a coordination number of 2, meaning that each Ag+ ion is coordinated with two NH3 ligands. This coordination number is determined by the number of bonds formed between the metal ion (Ag+) and the ligands (NH3 in this case). In the reaction Ag + 2NH3 = Ag(NH3)2+, two ammonia molecules are needed to fully coordinate with one Ag+ ion, resulting in the formation of the Ag(NH3)2+ complex.
As for the product, Ag(NH3)2+ is not considered a salt compound. It is a complex ion, where the central Ag+ ion is bonded to two NH3 ligands. Complex ions are formed when a metal ion binds to one or more ligands. In this case, Ag(NH3)2+ is a coordination complex formed by the coordination of Ag+ ion with two NH3 ligands.