Phosphorus pentachloride decomposes according to the chemical equation

Question

PCl5<-->PCl3 +Cl2
A 0.260 mol sample of PCl5(g) is injected into an empty 2.75 L reaction vessel held at 250 °C. Calculate the concentrations of PCl5(g) and PCl3(g) at equilibrium.

Please help I'm not sure where to go after you solved for x (Using the quadratic formula)

I got x=0.0921

is this correct? and how do i get the PCl5 and PCl3 from that?

Answer 1

I can't check this without knowing Kc.
If your value of x is correct that is the value of PCl3 and Cl2 because you probably did it this way.
........PCl5 ==> PCl3 + Cl2
I.......0.0945.....0.....0
C.........-x.......x......x
E.......0.0945-x...x......x
You can see x = (PCl3) = (Cl2) while (PCl5) = 0.0945-x

Answer 2

Sorry Kc is 1.8 at 250 degree C

Answer 3

You can check these things by substituting your value of x into the Kc expression and see if you come out with 1.8. I did this with 0.0921 and it doesn't pan out. When I solve the quadratic I obtained 0.09 for x and that checks out.

Answer 4

Phosphorus pentachloride gas, PCl5(g), will decompose to phosphorus trichloride,
PCl3(g), and chlorine, Cl2(g), at 160⁰C. In a sealed vessel, the reaction will proceed
to equilibrium:
PCl5(g) ↔ PCl3(g) + Cl2(g)
A chemist places 3.00 mol of phosphorus pentachloride gas into a sealed 1.50 L
flask at 160⁰C. At equilibrium, he observes there is 0.300 mol of phosphorus
trichloride gas and some chlorine gas. Calculate the equilibrium concentrations of
gaseous phosphorus pentachloride and chlorine gas. (6 points)

Answer 5

PCl5(g) ↔ PCl3(g) + Cl2(g)
A chemist places 3.00 mol of phosphorus pentachloride gas into a sealed 1.50 L
flask at 160⁰C. At equilibrium, he observes there is 0.300 mol of phosphorus
trichloride gas and some chlorine gas. Calculate the equilibrium concentrations of
gaseous phosphorus pentachloride and chlorine gas. (6 points)