kp and kc relationship

Question

For the reaction PCl₅(g) ⇌ PCl₃(g) + Cl₂(g), the relationship between Kp and Kc is:

RankGuru · Accepted Answer

The general relationship between the equilibrium constant in terms of partial pressures ($K_p$) and concentrations ($K_c$) is:
$K_p = K_c (RT)^{\Delta n_g}$
- $\Delta n_g = (	ext{moles of gaseous products}) - (	ext{moles of gaseous reactants})$
For $PCl_5(g) ightleftharpoons PCl_3(g) + Cl_2(g)$:
- $\Delta n_g = (1 + 1) - (1) = 2 - 1 = 1$
Substituting into the formula:
$K_p = K_c (RT)^1 \implies K_p = K_c(RT)$

Rank Guru

kp and kc relationship

Select the correct option: