Question

At $550K$,$K_c$ for the reaction, $X\left(g\right)+Y\left(g\right)\leftrightharpoons Z\left(g\right)$, is ${10}^{4}mol{L}^{-1}$. 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 $\left[Z\right]$ in $mol{L}^{-1}$ at equilibrium?

Answer 1

$\left[X\right]=\frac{1}{2}\left[Z\right]$ and $\left[Y\right]=\left[Z\right]$

$K_c=\frac{\left[Z\right]}{\left[X\right]\left[Y\right]}=\frac{\left[Z\right]}{\frac{1}{2}\left[Z\right]\times \left[Z\right]}={10}^4$

$\therefore \left[Z\right]=2\times {10}^{-4}$