Question

The equilibrium concentrations of X,Y and $Y{X}_2$ are 4, 2 and 2 respectively for the equilibrium $2X\left(g\right)+Y\left(g\right)\iff Y{X}_2\left(g\right)$. The value of equilibrium constant $k_c$ is:

• A. 0.0625
• B. 0.625
• C. 0.0628
• D. 0.628

Answer 1

Answer: (A)

0.0625

The equilibrium reaction is $2X\left(g\right)+Y\left(g\right)\iff Y{X}_2\left(g\right)$.
The expression for the equilibrium constant is $K_c=\frac{\left[Y{X}_2\right]}{\left[X{]}^2\right[Y]}$.
Substitute values in the above expression.
$K_c=\frac{2}{4^2\times 2}=0.0625$.