NEED HELP FAST!!

Question

At a certain temperature,  0.760 mol SO3  is placed in a  4.50 L  container.

2SO3(g)↽−−⇀2SO2(g)+O2(g)

At equilibrium,  0.160 mol O2  is present. Calculate  𝐾c.

Answer 1

Starting Concentration SO3 : 0.760 mol/4.50 L = 0.169M

2SO3 -> 2SO2 O2

I 0.169 0 0

C -2x +2x +x

E 0.169-2x 2x x

Now: you have 0.160 mol O2, you must find molarity at equilibrium. .160mol/4.50 L = 0.0356M

Now, at equilibrium, the concentration of O2 = "x", so you can set up Kc as follows:

( [SO2]^2 x [O2] ) / ([SO3]^2) = ( [0.0711]^2 x [0.0356] ) / ([0.0979]^2)

Which gives you the answer, 0.0188.