Question

At 550 K, the $K_c$ for the following reaction is ${10}^{-4}mo{l}^{-1}lit.$
$X\left(g\right)+Y\left(g\right)\iff Z\left(g\right).$

At equilibrium, it was observed that :$\left[X\right]=\frac{1}{2}\left[Y\right]=\frac{1}{2}\left[Z\right]$. What is the value of $\left[Z\right]$ ($inmolli{t}^{-1}$) at equilibrium ?

• A. $2\times {10}^{-4}$
• B. ${10}^{-4}$
• C. $2\times {10}^4$
• D. ${10}^4$

Answer 1

The correct option is C $2\times {10}^4$

The expression for equilibrium constant for the given reaction is given as:

$K_c=\frac{Z}{X.Y}$

$\therefore K_c=\frac{\left[Z\right]}{\left(0.5\right[Z\left]\right)\left[Z\right]}=\frac{2}{\left[Z\right]}$
$\left[Z\right]=\frac{2}{K_c}=2\times {10}^4$