Question

5 mol $PC{l}_5$(g) an one mole $N_2$ gas is placed in a closed vessel. at equillibrium $PC{l}_5$(g) decomposes by 20% and total pressure in the container is found to be 1 atm. the $k_P$ for the equillibrium
$PC{l}_5\left(g\right)\leftrightharpoons PC{l}_3\left(g\right)+C{l}_2\left(g\right)$ is:

• A. 1/24 atm
• B. 1/4 atm
• C. 1/16 atm
• D. 1/28 atm

Answer 1

The correct option is D 1/28 atm

To find $kp$fullsize.png)

Total moles at equb" $=4+1+1=6$

but 1 mole of $N_2$ also $=6+1=7$

$\begin{array}{cc}{K}_p& =\frac{K_{PPC{l}_3}\times K_{PC{l}_2}}{K_{PPC{l}_5}}\\ & =\frac{\frac{1}{7}\times \frac{1}{2}}{\frac{4}{7}}\\ & =\frac{1}{28}\\ \text{Hence, (D) is correct}& \end{array}$