Help with equilibrium composition of a gaseous mixture?

Question

The equilibrium constant Kc for the reaction
PCl3(g) + Cl2(g) <--> PCl5(g)

equals 49 at 230C. If 0.400 mol each of phosphorus thrichloride and chlorine are added to a 4.00 L reaction vessel, what is the equilibrium, what is the equilibrium composition of the mixture at 230C?

Help me with this problem, thanks in advanced

Answer 1

The equilibrium constant is equal to the conentration of the product divided by the conc. of the 2 reactants multiplied

K eq = (PCl5) / (PCL3)(Cl2)

The total amount of gas present will be 0.800 moles, composed of the 3 gases. The PCl3 and Cl2 will be equal.

Set PCL3 and Cl2 as X moles and PCL5 as 0.800 -XE2

K eq = 49. Now you can solve for all th eparts.

You have all of the data points and can solve for the concentration