Question

Before any reaction occurs, the concentrations of A and B in the reaction below are each 0.03900 M . What is the equilibrium constant if the concentration of A at equilibrium is 0.01365 M ? 2A(aq)+B(aq)⇌2C(aq) Round your answer to one decimal place.

Answer 1

Explanation:

As the given reaction is as follows.

          $2A(aq) + B(aq) \rightleftharpoons 2C(aq)$

Initial:    0.039         0.039                0

Equilbm: 0.01365   0.02535         0.02535

Now, expression for $K_{c}$ of the given reaction is as follows.

            $K_{c} = \frac{[C]^{2}}{[A]^{2}[B]}$

Putting the given values into the above formula as follows.

             $K_{c} = \frac{[C]^{2}}{[A]^{2}[B]}$

           $K_{c} = \frac{(0.02535)^{2}}{(0.01365)^{2} \times (0.02535)}$

                      = $1.360 \times 10^{2}$

                      = 136

Thus, we can conclude that the equilibrium constant for the given reaction is 136.