Assuming that the reaction from A and C to AC5 is only one-step (or an elementary reaction) with a balanced chemical reaction of:
A + 5 C ---> AC5
Therefore the formation constant can be easily calculated using the following formula for formation constant:
Kf = product of products concentrations / product of reactants concentration
Kf = [AC5] / [A] [C]^5
---> Any coefficient from the balanced chemical reaction becomes a power in the formula
Substituting the given values into the equation:
Kf = 0.100 M / (0.100 M) (0.0110 M)^5
Kf = 6,209,213,231
or in simpler terms
Kf = 6.21 * 10^9 (ANSWER)