The equilibrium constant for the reaction $w+x\rightleftharpoons$ y + z is 9. If one mole of each of w and x are mixed and there is no change in volume, the number of moles of y for formed is

$$\begin{gathered} \mathrm{W} + \mathrm{X} \rightleftharpoons \mathrm{Y} + \mathrm{Z} \mathrm{K}=9 \\ \mathrm{Initia} 1 1 0 0 \\ \mathrm{At}. \mathrm{eq}. 1-\mathrm{x} 1-\mathrm{x} \mathrm{x} \mathrm{x} \\ \mathrm{K}=9=\frac{{\mathrm{x}}^2}{(1-\mathrm{x}{)}^2} \\ \therefore \mathrm{x}=0.75 \\ \text{ Moles of }\mathrm{y}=0.75 \end{gathered}$$