Compounds A, B, and C react according to the following equation.?

Question

3A(g) + 2B(g) <==> 2C(g)

At 100°C a mixture of these gases at equilibrium showed that [A] = 0.855 M, [B] = 1.23 M, and [C] = 1.75 M. What is the value of Kc for this reaction?

A. 0.309

B. 0.601

C. 1.66

D. 3.24

E. > 10

Answer 1

The Kc for the given reaction is:

Kc = [C]^2 / [A]^3 [B]^2

Take note that:

* the products are on the numerator

* the reactants are on the denominator

* the products and reactants are raised to their respective stoichiometric (i.e. accdg to the chemical equation) coefficients

* the concentrations indicated are the concentrations at equilibrium

So it is just a matter of substituting the given values:

Kc = (1.75)^2 / (0.855)^3 (1.23)^2

Kc = 3.24

The answer is D