Answer :
Answer : The concentration of [tex]COF_2[/tex] remains at equilibrium will be, 0.37 M
Explanation : Given,
Equilibrium constant = 4.90
Initial concentration of [tex]COF_2[/tex] = 2.00 M
The balanced equilibrium reaction is,
[tex]2COF_2(g)\rightleftharpoons CO_2(g)+CF_4(g)[/tex]
Initial conc. 2 M 0 0
At eqm. (2-2x) M x M x M
The expression of equilibrium constant for the reaction will be:
[tex]K_c=\frac{[CO_2][CF_4]}{[COF_2]^2}[/tex]
Now put all the values in this expression, we get :
[tex]4.90=\frac{(x)\times (x)}{(2-2x)^2}[/tex]
By solving the term 'x' by quadratic equation, we get two value of 'x'.
[tex]x=1.291M\text{ and }0.815M[/tex]
Now put the values of 'x' in concentration of [tex]COF_2[/tex] remains at equilibrium.
Concentration of [tex]COF_2[/tex] remains at equilibrium = [tex](2-2x)M=[2-2(1.219)]M=-0.582M[/tex]
Concentration of [tex]COF_2[/tex] remains at equilibrium = [tex](2-2x)M=[2-2(0.815)]M=0.37M[/tex]
From this we conclude that, the amount of substance can not be negative at equilibrium. So, the value of 'x' which is equal to 1.291 M is not considered.
Therefore, the concentration of [tex]COF_2[/tex] remains at equilibrium will be, 0.37 M