Answer to Question #142172 in Physical Chemistry for Iqfa

Question

For the reaction CO2(g) + H2(g) = CO(g) + H2O(g)
the equilibrium constant at 1000 K is 0.53.
(a) If a mixture at equilibrium in a 1 dm3 vessel contains 0.25 mole of CO and 0.6 mole of H2, how
many moles of H2O are there in the vessel?
(b) 5 moles of inert gas are added to the equilibrium mixture containing 1 mole of H2 and 1 mole of CO2
in 1 dm3 vessel. Predict equilibrium concentration of CO2 and H2O.

Answer 1

Solution.

(a)

$K = \frac{x^2}{(0.25-x)\times(0.6-x)}$

x = 0.15 M

n(H2O) = 0.15 mol

(b)

Since the inert gas does not appear in the equilibrium constant, the number of moles of substances in equilibrium remains constant.

x = 0.53 M

n(H2O) = 0.53 mol

n(CO2) = 1 mol

Answer:

(a)

n(H2O) = 0.15 mol

(b)

n(H2O) = 0.53 mol

n(CO2) = 1 mol