Final answer:
The equilibrium concentrations of Cl2, F2, and ClF at 2500 K are 0.126 M, -0.144 M, and 1.159 M, respectively.
Step-by-step explanation:
To calculate the equilibrium concentrations of Cl2, F2, and ClF, we can use the equilibrium constant Kc and the initial concentrations of the reactants. Given that Kc = 20.0 at 2500 K, we can set up an ICE (Initial, Change, Equilibrium) table to solve for the equilibrium concentrations.
Initial concentrations: [Cl2] = 0.468 M, [F2] = 0.450 M, [ClF] = 0.862 M
Using the stoichiometry of the balanced equation, the change in concentration of Cl2 and F2 will be -2x (since they react to form 2 moles of ClF), and the change in concentration of ClF will be +x (since it is formed from the reaction).
After applying the equilibrium expression, we get: Kc = [ClF]^2 / ([Cl2] * [F2]) = 20.0
Substituting the given initial concentrations and solving for x, we find that x = 0.297 M. Therefore, the equilibrium concentrations are: [Cl2] = 0.468 M - 2x = 0.468 M - 2(0.297 M) = 0.468 M - 0.594 M = 0.126 M, [F2] = 0.450 M - 2x = 0.450 M - 2(0.297 M) = 0.450 M - 0.594 M = -0.144 M (negative value indicates that F2 is completely consumed), and [ClF] = 0.862 M + x = 0.862 M + 0.297 M = 1.159 M.