9/16/2009
1
Class 10 – Wednesday, September 14th
Chemical Equilibrium
Multiple Reactions, Yield, &
Selectivity
Water Gas Shift Equilbrium
CO (g) + H2O (g) ÍÎ CO2(g) + H2(g)
For reaction at equilibrium, the mole fractions of the
four reactive species satisfy the relation:
yCO2 yH2
-------------- = K (T), equilibrium constant
yCO yH2O
CO(g) + H
2
O(g) <==> CO
2
(g) + H
2
(g)
1 mol CO
2 mol H
2
OK
eq
= 1
y
CO2
y
H2
K
e
q
= ---------------- = 1
q
y
CO
y
H2O
Calculate the Equilibrium Composition
CO(g) + H
2
O(g) <==> CO
2
(g) + H
2
(g)
1 mol CO
2 mol H
2
OK
eq
= 1
y
CO2
y
H2
K
eq
= ---------------- = 1
y
CO
y
H2O
