Question

The equilibrium constant $K_c$ for the reaction $P_{4\left(g\right)}\rightleftharpoons 2P_{2\left(g\right)}$ is 1.4 at ${400}^{o}C$. Suppose that 3 moles of $P_{4(g})$ and 2 moles of $P_{2\left(g\right)}$ are mixed in 2 litre container at ${400}^{o}C$. What is the value of reaction quotient $\left(Q_c\right)$?

• A. $\frac{3}{2}$
• B. $\frac{2}{3}$
• C. 1
• D. $\frac{1}{2}$

Answer 1

The correct option is B $\frac{2}{3}$

$P_{4\left(g\right)}\rightleftharpoons 2P_{2\left(g\right)}{K}_C=\frac{{\left[P_2\right]}^2}{\left[P_4\right]}=1.4K_C^{{}^{\prime }}=\frac{1^2}{\frac{3}{2}}=\frac{2}{3}$