Question

A mixture initially contains A , B , and C in the following concentrations: [A] = 0.300 M , [B] = 1.15 M , and [C] = 0.700 M . The following reaction occurs and equilibrium is established:

A+2B⇌C

At equilibrium, [A] = 0.120 M and [C] = 0.880 M . Calculate the value of the equilibrium constant, Kc .

Answer 1

             A    + 2B    <===> C

initial       0.3 M 1.15 M     0.7 M

change       0.18 M      2*0.18 M       0.18 M

equilibrium 0.12 M    0.79 M     0.88 M

   Kc = [C]/[A][B]^2

      = 0.88/(0.12*0.79^2)

      = 11.75