Question

A reaction at equilibrium involving 2 moles each of $PC{l}_5,PC{l}_3,$ and $C{l}_2$ is maintained at ${250}^{o}C$ and a total pressure of 3 atm. The value of $K_p$ is :
Given: $PC{l}_5\rightleftharpoons PC{l}_3+C{l}_2$

• A. 5
• B. 4
• C. 8
• D. 1

Answer 1

The correct option is D 1

$\begin{array}{cccccc}& PC{l}_5& \rightleftharpoons & PC{l}_3& +& C{l}_2\\ Atequilibrium& 2& & 2& & 2\end{array}$
$P_{C{l}_5}=\frac{2}{6}\times 3,P_{P_{C{l}_3}}=\frac{2}{6}\times 3,P_{C{l}_2}=\frac{2}{6}\times 3$
$K_p=\frac{p_{PC{l}_3}\times p_{C{l}_2}}{p_{PC{l}_5}}=\frac{1\times 1}{1}=1$