LECTURE 2
FUNDAMENTALS – THERMODYNAMICS,
CHEMICAL EQUILIBRIUM, KINETICS, CATALYSIS
THE WATER GAS SHIFT REACTION
The water-gas shift reaction (WGS) is a chemical reaction in which carbon
monoxide reacts with water vapor to form carbon dioxide and hydrogen:
CO(g) + H2O(g) → CO2(g) + H2(g)
The water-gas shift reaction is an important industrial reaction.
It is important for the production of high purity hydrogen for use in ammonia
synthesis. The water-gas shift reaction was discovered by Italian physicist Felice
Fontana in 1780. The reaction is slightly exothermic, yielding 41.1 kJ (10 kcal)
per mole.
THE WATER GAS SHIFT REACTION
The changes in concentration with time for the Water-Gas Shift Reaction when
starting with equimolar amounts of CO and H2O
THE WATER GAS SHIFT REACTION
LAW OF MASS ACTION
For a general reaction,
aA + bB  cC + dD
Where all reactants and products are in the gas
phase, the equilibrium constant is given as,
FREE ENERGY AND EQUILIBRIUM
THE EFFECT OF PRESSURE ON ∆G OF A GAS
At conditions away from equilibrium,
Chemical Equilibrium
The ∆G for the water gas shift reaction is -28 kJ/mol.
What is the maximum % yeild of H2 gas from this
reaction if 1.0 atm of CO and 1.0 atm of water
vapor are mixed and allowed to react to equilibrium?
LE CHATELIER’S PRINCIPLE
TYPES OF APPLIED STRESS
Effect of P on equilibrium Composition
SAMPLE PROBLEM
Max yeild of ammonia from the reaction of N2 and
H2? ∆H = -46kJ /mol
TEMPERATURE DEPENDENCE of K
KINETICS
KINETICS