Question

If 8g mol of ${PCl}_5$ heated in a closed vessel of 10L capacity and 25% of its dissociates into ${PCl}_3$ and ${Cl}_2$ at the equilibrium then value of Kp will be equal to:(P is total pressure)

• A. P/30
• B. P/15
• C. 2/3P
• D. 3/2P

Answer 1

The correct option is B P/15

${PCl}_5\rightleftharpoons {PCl}_3+{Cl}_2$

initial $\frac{8}{10}$ $0$ $0$ $K_P=frac{P}_{{PCl}_3}\times P_{{Cl}_2}{P}_{{PCl}_5}$

$25$% disso $\frac{8}{10}-\frac{2}{10}$ $2/10$ $2/10$ $=\frac{{P_T}^2(x_{{PCl}_3}\times x_{{Cl}_2})}{P_T{x}_{{PCl}_5}}$

ciation $K_P=P_T/15\Leftarrow P_T\left(\frac{2/10\times 2/10}{6/10}\right)$