equilibrium equation A + B = C

Question

There is given  the equilibrium constant  k = [A][B]/[C]

find the value of constant K

There is given information:

3C=D (Kc=7.9*10^-4)

D=3A+3B (Kc= 6.7*10^-2)

Answer 1

Solving the problem can be a little bit tricky, so you can try this way:

3C = D       k1 = [D]/[C]^3 = 7.9*10^-4

D = 3A + 3B     k2 = [A] ^3/[B]^3    = 6.7*10^-2

k1 x k2 = [A]^3 [B]^3 / [C]^3  = {[A][B]/[C]} ^3