Question

For the equilibrium $2S{O}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2S{O}_3\left(g\right)$ the concentration of each substance at equilibrium is: $\left[S{O}_2\right]=0.60M,\left[O_2\right]=0.82M$ and $\left[S{O}_3\right]=1.90M$, the K${}_c$ is:

• A. 1.2229 $mol{L}^{-1}$
• B. 12.2 $mol{L}^{-1}$
• C. 6.1145 $mol{L}^{-1}$
• D. 18.22 $mol{L}^{-1}$

Answer 1

The correct option is B 12.2 $mol{L}^{-1}$

The equilibrium reaction is $2S{O}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2S{O}_3\left(g\right)$.
The expression for the equilibrium constant is $K_C=\frac{[S{O}_3{]}^2}{\left[S{O}_2{]}^2\right[O_2]}$.
Substitute values in the above expression.
$K_C=\frac{{1.9}^2}{{0.6}^2\times 0.82}{M}^{-1}=12.237mol{L}^{-1}$.