Starter quiz
- Which of these statements are required for a dynamic equilibrium to be established?
- all particles to be in the gas state
- closed system ✓
- equal amounts of reactants and products
- equal reaction rates for forward and backward reaction ✓
- reversible reaction ✓
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- The direction of reversible reactions can be influenced by changing conditions, e.g. an exothermic reaction is favoured by lowering the temperature, but at the same time the reaction rate ______.
- 'decreases' ✓
- True or false? At dynamic equilibrium all bonds between all atoms need to be broken and new bonds need to be formed.
- True
- False ✓
- Consider this reaction: CaCO ⇌ CaO + CO What would happen if this was done in an open system?
- the carbon dioxide gas leaves and the backward reaction can no longer occur ✓
- the forward reaction stops and you are left with only calcium carbonate
- there will be an equilibrium with only calcium carbonate and calcium oxide
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- Industrial chemistry is different from chemistry in a school lab or a research lab. The ______ of the work is larger; therefore the risks and safety measures are larger too.
- 'scale' ✓
What is wrong with the graph below?- at equilibrium the rates of the forward and backward reaction must be equal ✓
- the graphs for the forward and backward reaction have been swapped
- the reactants and products should be mentioned in a rate of reaction graph
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Exit quiz
- Traditional ammonia produced through the Haber process is called grey ammonia. Match the following terms with the correct definitions.
- blue ammonia⇔traditional ammonia, but involving carbon capture of the emissions ✓
- green ammonia⇔ammonia produced through 100% renewable and carbon-free processes ✓
- Grey ammonia, through the Haber process, is the most common. Industrial production requires high pressure, large but safe apparatus, and a lot of energy. Which of the following statements are correct?
- ammonia production is a reversible reaction ✓
- at equilibrium, there is ammonia but also nitrogen and hydrogen ✓
- high pressures require strong equipment and a lot of energy ✓
- high temperature is needed to increase the rate of reaction ✓
- nitrogen and hydrogen are wasted when ammonia is condensed and removed
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- The conditions for the Haber process are:
- a compressor
- a cooling tank
- an iron catalyst ✓
- a pressure of 200 atm ✓
- a temperature of 450C ✓
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- In industry, ammonia is made with nitrogen from air, and hydrogen from natural gas, using the Haber process. Put the steps in order:
- 1⇔nitrogen (from air) and hydrogen (from natural gas) are brought together
- 2⇔a compressor increases the pressure to 200 atm
- 3⇔the gas mixture is heated to 450C in a tank containing iron catalyst
- 4⇔the mixture enters a cooling tank so that ammonia is condensed
- 5⇔liquid ammonia is collected
- 6⇔unreacted nitrogen and hydrogen are recycled to make more ammonia
- Clara, Haber’s wife, was a chemist and pacifist, believing war and violence are unjustifiable. She felt her husband’s research was a “perversion of the ideals of science”. What made her feel that way?
- she felt passionately that science must not be used for chemical warfare ✓
- she thought making ammonia was a bad influence on people’s health
- she was forced to stop being a chemist because he was already a chemist
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- As the global population continues to grow, production of ammonia will continue. What is ammonia not used for?
- burning in engines
- chemical store for renewable energy
- cooling household refrigerators ✓
- making cleaning products
- making fertilisers for agriculture
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Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- In a reversible reaction the desired product needs to be continuously removed from the reaction.
- Natural gas is a feedstock for industrial production of ammonia.
- Hydrogen, one of the raw materials in ammonia production, is produced from natural gas and steam.
- In industry, the Haber process is typically performed at 150-300 atmospheres, 400-450°C, with an iron catalyst.
- Ammonia production is energy-intensive and releases large amounts of carbon dioxide, contributing to global emissions.
Common misconception
Students find it difficult to understand why continuous removal of ammonia is required to increase yield.
Highlight that the Haber Process is a dynamic equilibrium. If ammonia is not continuously removed, the equilibrium will shift back towards the reactants, reducing the yield.
Keywords
Natural gas - A mixture of gases which are rich in hydrocarbons, consisting largely of methane.
Feedstock - Refers to the raw materials used in chemical processes to produce other substances.
Raw material - The starting materials used to make products are known as the raw materials.
Haber process - An industrial method for producing ammonia from nitrogen and hydrogen.
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