Question

For the reaction given, $2N{O}_2\left(g\right)\leftrightharpoons 2NO\left(g\right)+O_2\left(g\right)$, $K_c=1.8\times {10}^{-6}$ at ${184}^{\circ }C$ and $R=0.08311$ kJ/mol.K. When $K_p$ and $K_c$ are compared at ${184}^{\circ }C$, it is found that:

• A. Whether $K_p$ is greater than, less than or equal to $K_p$ depends upon the total gas pressure
• B. $K_p=K_c$
• C. $K_p$ is less than $K_c$
• D. $K_p$ is greater than $K_c$

Answer 1

Answer: (D)

$K_p$ is greater than $K_c$

The relation between $K_p$ and $K_c$ is as follows:

$K_p=K_c\times (RT{)}^{\Delta n}$

GIven the reaction: $2N{O}_2\left(g\right)\iff 2NO\left(g\right)+O_2\left(g\right)$

Therefore, $\Delta n=1$.

$K_p=K_c\times \left(RT\right)$

The value of $RT>1$ as $T={184}^{o}C=457K$ and $R=0.08311$ kJ/mol.K.

$\therefore K_p>K_c$.