Question

For a gaseous homogeneous reaction at equilibrium, a number of moles of products is greater than the number of moles of reactants. Is K_C is larger or smaller than K_p?

Answer 1

For a homogeneous reaction at equilibrium, number of moles of products (n_p) are greater than the number of moles of reactants (n_R) then

∆n_g = + ve

n_p > n_R

∆n_g = + ve

If ∆n_g is ve, K_p value is greater than K_C

K_p = K_C. (RT)^+ve

K_p > K_C

Example: \[\ce{PCl5 <=> PCl3(g) + Cl2(g)}\]

2 – 1 = 1

K_p = K_C (RT)¹

K_p > K_C