Question

At 1000 K, the value of $K_p$ for the reaction: $A\left(g\right)+2B\left(g\right)\rightleftharpoons 3C\left(g\right)+D\left(g\right)$ is 0.05 atmosphere. The value of $K_C$ in terms of R would be :

• A. 20000 R
• B. 0.02 R
• C. $5\times {10}^{-5}R$
• D. $5\times {10}^{-5}\times R^{-1}$

Answer 1

The correct option is D $5\times {10}^{-5}\times R^{-1}$

$K_p$ is the pressure constant at equilibrium and $K_c$ is the equilibrium constant.

Relation between $K_p$ and $K_c$ is

$K_p=K_c(RT{)}^{\Delta n_g}-------(1)$

Where,

R = Universal Gas Constant

T = Temperature

$\Delta n_g=(n_p-n_R)g$

$A\left(g\right)+2B\left(g\right)\rightleftharpoons 3C\left(g\right)+D\left(g\right)$

$\Delta n_g=4-3=1$

$K_p=0.05atm$

from equation (1)

$0.05=K_c(R\times 1000)$

$K_c=5\times {10}^{-5}\times R^{-1}$

Option D is correct answer