Question

For the reaction CO (g) + Cl2 (g) = COCl2 (g) , the Kp/ Kc =? Answer is 1/RT

Answer 1

CO (g) + Cl₂ <==> COCl₂ (g)

In given equation
Δn = 1 - (1 + 1) = -1

Relation between kp and kc is
kp = kc (RT)^(Δn)

kp / kc = (RT)^-1
= 1 / (RT)

∴ Ratio of kp and kc is 1 : RT

Answer 2

Answer: $\frac{K_p}{K_c}=\frac{1}{RT}$

Explanation:

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

where:

$K_p$ = equilibrium constant in terms of pressure

$K_c$ = equilibrium constant in terms of concentration

$\Delta n_g$= number of moles of gaseous products - number of moles of gaseous reactants

R = gas constant

T= temperature

For reaction; $CO(g)+Cl_2(g)\rightarrow COCl_2(g)$

$\Delta n_g$= number of moles of gaseous products - number of moles of gaseous reactants= 1-(1+1) = 1-2 = -1

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

$\frac{K_p}{K_c}=\frac{1}{RT}$