Since Q is greater than b2, equilibrium must be reestablished by shifting the reaction
to the left, decreasing the concentration of Ag(NH3)2
+. Furthermore, this new
equilibrium position lies toward the side of the equilibrium reaction with the
greatest number of solutes (one Ag+ ion and two molecules of NH3 versus the single
metal–ligand complex). If the solution of Ag(NH3)2
+ is concentrated, by evaporating
some of the solvent, equilibrium is reestablished in the opposite direction.
This is a general conclusion that can be applied to any reaction, whether gas-phase,
liquid-phase, or solid-phase. Increasing volume always favors the direction producing
the greatest number of particles, and decreasing volume always favors the
direction producing the fewest particles. If the number of particles is the same on
both sides of the equilibrium, then the equilibrium position is unaffected by a
change in volume.