Carbonyl fluoride COF2 is an important intermediate used in

Carbonyl fluoride, COF2, is an important intermediate used in the production of fluorine-containing compounds. For instance, it is used to make the refrigerant carbon tetrafluoride, CF4 via the reaction 2COF2(g)CO2(g)+CF4(g), Kc=5.30 If only COF2 is present initially at a concentration of 2.00 M, what concentration of COF2 remains at equilibrium?

Solution

ICE Table:

                    [COF2]              [CO2]               [CF4]             

initial             2.0                 0                   0                 

change              -2x                 +1x                 +1x               

equilibrium         2.0-2x              +1x                 +1x               

Equilibrium constant expression is
Kc = [CO2]*[CF4]/[COF2]^2
5.3 = (1*x)^2/(2-2*x)^2
sqrt(5.3) = (1*x)/(2-2*x)
2.3022 = (1*x)/(2-2*x)
4.60435-4.60435*x = 1*x
4.60435-5.60435*x = 0
x = 0.82157

At equilibrium:
[COF2] = 2.0-2x = 2.0-2*0.82157 = 0.35687 M

Answer: 0.357 M