The value of Kc for the reaction below is 1.6

Question

C(s)+CO2(g)=2CO(g)
What is the equilibrium concentration of CO when [CO2]=.50M?
The usual ICE table doesn't work for me.

C(s)+CO2(g)=2CO(g)
I - 0
C -x +2x
E .50 +2x

1.6=[2x]^(2)/(.50)
That's how I did it but the answer is .89 and I didn't get that.

Answer 1

I don't get 0.89 either. What I don't know is about the equilibrium. Is that 0.50 quoted for CO2 equilibrium concn or initial concn? I worked it both ways and I obtained 0.80 if the 0.5M CO2 is at equilibrium. If initial then I used
1.6 = (2x)^2/(0.5-x) and obtained 0.29.

Answer 2

equi eq:
1.6=x^2/0.5 ; x= equi conc [CO]
x=0.894427191
do not consider [C] since it exists as solid in the equation