A closed system contains the following equilibrium reaction:
A(g) + B(g) <=> C(g) + D(g)
At a specific temperature, the equilibrium constant (Kc) for this reaction is determined to be 4.0. If the initial concentrations of A and B are both 1.0 M and the initial concentrations of C and D are both 0 M, what will be the equilibrium concentrations of all species in the system?