Question

For the reaction: $2NOCl\left(g\right)\rightleftharpoons 2NO\left(g\right)+{Cl}_2\left(g\right)$, $K_c$ at ${427}^{o}C$ is $3\times {10}^{6}M$. The value of $K_p$ is nearly:

• A. $7.5\times {10}^{-5}$
• B. $2.5\times {10}^{-5}$
• C. $2.5\times {10}^{-4}$
• D. $1.75\times {10}^{-4}$

Answer 1

The correct option is D $1.75\times {10}^{-4}$

For the reaction: $2NOCl\left(g\right)\rightleftharpoons 2NO\left(g\right)+{Cl}_2\left(g\right)$, $K_c$ at ${427}^{o}C$ is $3\times {10}^{-6}M$. The value of $K_p$ is nearly $1.75\times {10}^{-4}$.
$\Delta n=(2+1)-2=1$
$K_p=K_c(RT{)}^{\Delta n}$
$K_p=K_c(RT{)}^1$
$K_p=K_c\left(RT\right)$
$K_p=3\times {10}^{-6}M\times 0.08206Latm/mol/K\times (427+273)K$
$K_p=1.75\times {10}^{-4}atm$