Chemistry - Chemical Equilibrium Question with Solution | TestHub

Explain Question: The question is asking about the equilibrium concentration of A.

Concept: By combining the given equations we have to find the overall Kc , with the help of which we can find the concentration of A.

Solution:

$$\begin{array}{ll}\mathrm{A}(\mathrm{g})\rightleftharpoons 2\mathrm{B}(\mathrm{g})+\mathrm{C}(\mathrm{g})& {\mathrm{K}}_{{\mathrm{C}}_1}=400{\mathrm{M}}^2\\ [\mathrm{B}(\mathrm{g})\rightleftharpoons \mathrm{D}(\mathrm{g})+\mathrm{C}(\mathrm{g})]\times 2& {\mathrm{K}}_{{\mathrm{C}}_2}=10000{\mathrm{M}}^2\\ & \end{array}$$

Overall reaction

$\mathrm{A}(\mathrm{g})\rightleftharpoons 2\mathrm{D}(\mathrm{g})+3\mathrm{C}(\mathrm{g}){\mathrm{K}}_{\mathrm{C}}=4\times 10^6{\mathrm{M}}^4$

2M 0 0

x 4M 6M

${\mathrm{K}}_{\mathrm{C}}=4\times 10^6=\frac{4^2\times 6^3}{\mathrm{x}}$

$\mathrm{x}=8.64\times 10^{-4}\mathrm{M}$

Final Answer: (8.64)