Question
The equilibrium constant at 278K for 
is 
. In a solution in which copper has displaced some silver ions from the solution, concentration of Cu2+ ions is 1.8 x 10-2 mol L-1 and the concentration of Ag+ ions is 3·0 ×10–9 mol L–1. Is the system at equilibrium?
Solution
The given reaction in a state of equilibrium may be represented as:
Applying the law of chemical equilibrium
By convention, [Ag(s)] = 1 and (Cu(s)] = 1
Substituting,
Applying the law of chemical equilibrium
By convention, [Ag(s)] = 1 and (Cu(s)] = 1
Substituting,
which is same as for the reaction in equilibrium.
Hence the given system is in equilibrium.
