Question

The equilibrium concentration of $X,Y$ and $Y{X}_2$ are $4,2$ and $2$ moles respectively for the equilibrium $2X+Y\rightleftharpoons Y{X}_2$. The value of $K_c$ is:

• A. $0.625$
• B. $0.0625$
• C. $6.25$
• D. $0.00625$

Answer 1

The correct option is B $0.0625$

We have $2X+Y\leftrightharpoons Y{X}_2$

At equilibrium 4 2 2

So,

$K_c=\frac{\left[Y{X}_2\right]}{\left[2X{]}^2\right[Y{]}^1}$

$K_c=\frac{[2{]}^1}{\left[4{]}^2\right[2{]}^1}=\frac{2}{16\times 2}=\frac{1}{16}=0.0625$