Equilibria and Ammonia Flashcards
What is the Harber-Bosch Process
N2 + 3H2 2NH3 (exothermic)
-Ammonia is manufactured by reacting nitrogen and
hydrogen
What is a reversible reaction
A reaction whre the forward and backward reactions occur at equal rates
What are the raw materials for the Haber-Bosch Process
- Nitrogen obtained by Fractional Distillation of Air
- Hydrogen obtained from methane and steam
Describe the conditions of the Harber-Bosch Process
- Nitrogen and Hydrogen in a 1:3 volume ratio
- 400-450 degrees Celsius
- 200 atmospheres of pressure (atm)
- iron catalysts
- unreacted gases are recycled
Describe an account of the Harber Bosch Process
1) Gases passed over iton catalyst at abour 450 degress and 200 atm
2) Some of the hydrogen and nitrogen break down to form ammonia and vice versa
3) It is cooled so the ammonia condenses and is removed while the unused gases are recycled
What is Le Chatalier’s Principle
‘A system at equilibrium will react to oppose any change imposed on it’
Define Exothermic
reaction releases heat energy
Define Endothermic
Reaction takes in heat energy
Describe increasing of temp. on Equilibria
reaction proceeds in the endothermic direction
Describe decr. of temp. on Equilibria
reaction proceeds in the exothermic direction
Why is a compromise temp. used in the Harber-Bosch Process
As a lower temp. gives a higher yield of ammonia but too low a temp. and the rate will be too low
What is the effect of inc. pressure on equilibrium
equlibria moves to the side where there are less molecules
What is the effect of decr. pressure on equlibria
equlilbria shifts to side where there are more molecules
What is the danger of increasing pressure too much
too high a pressure leads to risk of explosion and equipment to withstand and use high pressure is very costly
What is the effect of adding reagents to equilibria
it shifts the equilibria to the forward direction (inc. yield of ammonia by recycling gases)
