Question

The equilibrium constant for the following reaction will be
$P_{4(s)} +5O_{2(g)} \rightleftharpoons P_4O_{10(s)}$

• A. $K_{c}=\frac{\left[P_{4}\right]\left[O_{2}\right]^{5}}{\left[P_{4}O_{10}\right]}$
• B. $K_{c}=\frac{1}{\left[O_{2}\right]^{5}}$
• C. $K_{c}=\frac{\left[P_{4}O_{10}\right]}{\left[P_{4}\right]\left[O_{2}\right]^{5}}$
• D. $K_{c}=\left[O_{2}\right]^{5}$

Answer 1

Answer: (B)

$P_{4(s)} +5O_{2(g)}\rightleftharpoons P_4O_{10(s)}$
Since concentration of solids is taken as $1$, expression for equilibrium constant involves only oxygen.
$K_{c}=\frac{1}{\left[O_{2}\right]^{5}}$