Question

An equilibrium mixture of $P{Cl}_5,P{Cl}_3$ and ${Cl}_2$ at a certain temperature contians $0.5\times {10}^{-3}M$ $P{Cl}_3$, $1.5\times {10}^{-2}$ $P{Cl}_3$ and $3\times {10}^{-2}M$ ${Cl}_2$. Calculate the equilibrium constant $K_c$ for the reaction $P{Cl}_5\left(g\right)\rightleftharpoons P{Cl}_3\left(g\right)+{Cl}_2\left(g\right)$

Answer 1

$\begin{array}{c}{K}_C=\frac{\left[PC{l}_3\right]\left[C{l}_2\right]}{\left[PC{l}_5\right]}\\ \Rightarrow \frac{3.0\times {10}^{-2}\times 1.5\times {10}^{-2}}{0.5\times {10}^{-3}}\Rightarrow 9\times {10}^{-1}\\ \Rightarrow K_C=0.9\end{array}$