7.19 A sample of pure PCl5 was introduced into an evacuated vessel at 473 K. After equilibrium was attained, concentration of PCl5 was found to be 0.5 × 10-1 mol L-1. If value of Kc is 8.3 × 10-3, what are the concentrations of PCl3 and Cl2 at equilibrium?
We have,
concentration of = 0.05 mol/L
and
Suppose the concentrations of both and at equilibrium be mol/L. The given reaction is:
at equilibrium 0.05
it is given that the value of the equilibrium constant,
Now we can write the expression for equilibrium as:
(approx)
Hence the concentration of and is 0.0204 mol / L