For the balanced reaction 2 K2O2 (aq) O2 (g) + 2 K2O (aq) a mixture of the follow was at equilibrium at 86 °C (atmospheric pressure) in a closed container:
[K2O2] = 0.400 M ; [K2O] = 0.315 M; [O2] = 0.066 M
Compute the equilibrium constant for this reaction.