Question

The equilibrium constant, Kc, for the following reaction is 83.3 at 500 K.

PCl3(g) + Cl2(g) PCl5(g)

Calculate the equilibrium concentrations of reactant and products when 0.309 moles of PCl3 and 0.309 moles of Cl2 are introduced into a 1.00 L vessel at 500 K.

[PCl3] = M

[Cl2] = M

[PCl5] = M

(please show work especially quadratic equation)