Final answer:
To determine the concentration of O₂ at equilibrium, write the equilibrium constant expression for the reaction, fill out an ICE table with initial, change, and equilibrium concentrations, then solve for the unknown concentrations and verify by substituting back into the equilibrium expression.
Step-by-step explanation:
To determine the concentration of O₂ at equilibrium, you need to write the equilibrium constant expression based on the balanced chemical equation of the reaction. The general form of the equilibrium constant expression for a reaction aA + bB ⇌ cC + dD is K = [C]^c[D]^d / [A]^a[B]^b, where the brackets denote the concentrations of the substances.
Once the equation is established, construct an ICE (Initial, Change, Equilibrium) table to keep track of the concentrations. After determining the initial concentrations and the changes that occur as the system reaches equilibrium, fill in the final concentrations.
With the equilibrium constant expression and ICE table ready, substitute the final equilibrium concentrations into the expression and solve for equilibrium concentrations. Finally, check your results by substituting the calculated concentrations back into the equilibrium constant expression to assure consistency with the value of K.
As an example, if we were solving for the concentration of CO in a reaction and found it to be 0.0746 M, we would use similar methods to determine the concentration of O₂.