Question

Given the reaction:
$A_{\left(g\right)}+B_{\left(g\right)}\rightleftharpoons 2C_{\left(g\right)}+D_{\left(g\right)}$
One mole of $A$ and one mole of $B$ are placed in a $1.0$ litre vessel. After equilibrium has been established, $0.4$ mole of $C$ is present in the vessel. Calculate $K_c$ for the reaction.

Answer 1

$A_{\left(g\right)}+B_{\left(g\right)}\rightleftharpoons {2C}_{\left(g\right)}+D_{\left(g\right)}$

$t=0$ $1$ $1$ $0$ $0$

$t=t_{eq}$ $1-\alpha$ $1-\alpha$ $\alpha$ $\alpha$

Given $2\alpha =0.4$

$\alpha =0.2$

$0.8$ $0.8$ $0.4$ $0.2$ moles = concentration

($\because$ volume 1 lit)

$K_C=\frac{{\left(0.4\right)}^2\times 0.2}{{\left(0.8\right)}^2}\Rightarrow \frac{0.2}{4}\Rightarrow 0.05$