Starter quiz
- The industrial method for producing ammonia from hydrogen and nitrogen is called the ______.
- 'Haber process' ✓
- What name is given to a substance that increases the rate of a reaction, by providing an alternative reaction pathway?
- 'catalyst' ✓
- Which of the following chemical reactions are exothermic?
- Photosynthesis
- Thermal decomposition
- Respiration ✓
- Combustion ✓
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- In an equation for a chemical reaction, what is the meaning of this symbol ⇌?
- 'reversible reaction' ✓
- Which of the following factors does not increase the rate of this chemical reaction? NaOH (aq) + HCl (aq) → H₂O (l) + NaCl (aq)
- Increasing the concentration
- Increasing the temperature
- Increasing the pressure ✓
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- What is normally used as a catalyst in the Haber process?
- 'iron' ✓
Exit quiz
- Match the following terms with the correct definitions.
- Equilibrium position⇔At equilibrium, the relative concentrations of reactants and products. ✓
- Dynamic equilibrium⇔Forward and reverse reactions occur at the same rate. ✓
- Reaction rate⇔Speed at which a chemical reaction takes place. ✓
- Contact process⇔Industrial method for producing sulfuric acid. ✓
- Haber process⇔Industrial method for producing ammonia. ✓
- Which of the following factors does not affect the position of equilibrium?
- Temperature
- Pressure
- Catalysts ✓
- Concentration
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- What impact would increasing the pressure have on this reversible reaction? 3H₂ (g) + N₂ (g) ⇌ 2NH₃ (g)
- The reaction rate would increase. ✓
- The reaction rate would decrease.
- The yield of ammonia would increase. ✓
- The yield of ammonia would decrease.
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- A reversible reaction is exothermic in the forward reaction. Which of the following statements about the reaction are correct?
- A high temperature would increase the rate of the reaction. ✓
- A high temperature would increase the yield.
- A high temperature would decrease the yield. ✓
- A high temperature would decrease the rate of reaction.
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- During a reversible reaction the desired product is removed, the pressure and temperature are kept constant. What impact does this have on the reaction?
- It decreases the concentration of the desired product (in the reaction mixture). ✓
- It shifts the equilibrium position towards the desired product. ✓
- It increases the rate of reaction.
- It decreases the yield of the desired product.
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- Why is ammonia manufactured at 200 atmospheres rather than the higher 400 atmospheres? 3H₂ (g) + N₂ (g) ⇌ 2NH₃ (g)
- Increasing the pressure would decrease the rate of reaction.
- Increasing the pressure would increase the cost. ✓
- Increasing the pressure would increase the equipment failure risk. ✓
- Increasing the pressure would decrease the yield.
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Worksheet
Presentation
Video
Lesson Details
Key learning points
- Industrial equilibria involve a trade-off between production rate and equilibrium position.
- Temperature, pressure, surface area, concentration, and catalysts impact rates and equilibrium, often in opposing ways.
- High pressures and temperatures boost reaction rates but must balance safety and cost.
- High pressures are costly and increase equipment failure risk.
- Low temperatures slow reactions but can favour desired product in exothermic reactions.
Common misconception
Higher temperature/pressure always increases the yield of products in equilibrium reactions.
High temperature can decrease yield in exothermic reactions by shifting equilibrium toward reactants; high pressures can decrease yield where there are fewer gaseous moles of reactants than products.
Keywords
Equilibrium position - refers to the relative concentrations of reactants and products in a reversible reaction at equilibrium.
Dynamic equilibrium - occurs in a closed system when the forward and reverse reactions of a reversible chemical reaction are occurring at the same rate; and the concentrations of reactants and products remain constant.
Reaction rate - is the speed with which a chemical reaction takes place, measured by the amount of a reactant used or amount of product formed in a given time.
Haber process - an industrial method for producing ammonia.
Contact process - an industrial method for producing sulfuric acid.