Starter quiz
- In research labs high, pressure apparatus is contained in small spaces to reduce risk. The large ______ of industry requires strong equipment as safety measures, to protect workers and the public.
- 'scale' ✓
- Sulfuric acid is corrosive. What warning symbol would you expect to see on a flask of concentrated sulfuric acid?
- A type of reaction in which energy is transferred from the reactants to the surroundings is called an ______ reaction.
- 'exothermic' ✓
- Making sulfuric acid in industry has environmental as well as economic implications. Which of these are environmental (positive as well as negative)?
- feedstock for other industry
- high emissions of CO ✓
- high energy use ✓
- unreacted gases can be recycled ✓
- use for petroleum refinery
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- All feedstocks are raw materials, but not all raw materials are feedstock. Which statements explain the difference?
- feedstock is a subset of raw materials, used in chemical processes ✓
- raw materials are always simpler, in chemical terms, than feedstocks
- raw materials are anything that can be used for making any product ✓
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- Many chemicals, including ammonia and sulfuric acid, are found in nature but in small quantities. Which of the following statements drive industrial chemistry?
- a growing world population needs more food and fertilisers ✓
- solutions can be found for energy use and environmental impacts ✓
- the natural sources of ammonia and sulfuric acid may run out
- there are significant economic implications from major industrial processes ✓
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Exit quiz
- Match the following terms with the correct definitions.
- Contact process⇔industrial method making sulfuric acid from sulfur, oxygen and water ✓
- corrosive⇔causing severe injury, damage or destruction by chemical action ✓
- exothermic reaction⇔reaction in which energy is transferred from reactants to surroundings ✓
- feedstock⇔raw materials used in chemical processes to make other substances ✓
- Haber process⇔industrial method for making ammonia from nitrogen and hydrogen ✓
- raw materials⇔any starting materials used to make any kind of products ✓
- The feedstocks of the Contact process are:
- hydrogen
- nitrogen
- oxygen ✓
- sulfur ✓
- water ✓
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- What are the reaction conditions for step 2 of the Contact process, which is 2SO + O ⇌ 2SO?
- iron catalyst
- pressure 1-2 atm ✓
- pressure 200 atm
- temperature 450C ✓
- vanadium (V) oxide catalyst ✓
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- Put the steps of the Contact process in order (note that the step for converting sulfur trioxide into sulfuric acid is split into two safe steps, rather than one dangerous one).
- 1⇔making sulfur dioxide, from S or CuS with excess oxygen
- 2⇔reversible reaction between SO and O to make SO
- 3⇔making oleum: SO + HSO →HSO
- 4⇔HSO + HO → 2HSO
- Step 1 of the Contact process, e.g. S+O →SO is an ideal set-up for step 2 where SO needs to become SO. Why is this?
- SO becomes SO without doing anything else
- SO is already mixed with O, ready for the next step ✓
- the reaction conditions are already ideal
- the unreacted gases can be recycled in step 1
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- Hypothetically, SO+HO→HSO, but this is never done. Why can we not just add sulfur trioxide to water to make sulfuric acid?
- fuming sulfuric acid is manageable, but clouds of sulfuric acid are not ✓
- sulfur trioxide plus water become something else, not sulfuric acid
- the reaction between sulfur trioxide and water is too slow
- the reaction is highly exothermic and creates dangerous clouds of sulfuric acid ✓
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Worksheet
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Presentation
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Video
Lesson Details
Key learning points
- The Contact Process involves the production of sulfur trioxide (SO₃) from sulfur dioxide (SO₂) using a catalyst.
- The process has three main stages: burning sulfur to produce SO₂, converting SO₂ to SO₃, then converting SO₃ to H₂SO₄.
- The conversion of SO₂ to SO₃ is a reversible reaction performed at 1-2 atmospheres and 450°C, using a V₂O₅ catalyst.
- Sulfuric acid production is energy-intensive and releases large amounts of CO₂, contributing to global emissions.
- Sulfuric acid is vital for various industries, such as: fertilisers, chemical manufacturing, and petroleum refining.
Common misconception
Students often assume that the production of sulfuric acid in the Contact Process is a one-step process (similar to the Haber process).
Clarify that the Contact Process involves multiple stages, each requiring specific conditions. Emphasise the importance of these conditions in maximising yield and minimising energy consumption.
Keywords
Raw material - The starting materials used to make products are known as the raw materials.
Feedstock - Refers to raw materials used in chemical processes to produce other substances.
Contact process - An industrial method for producing sulfuric acid by oxidising sulfur dioxide to sulfur trioxide.
Exothermic - A type of reaction in which energy is transferred from the reactants to the surroundings.
Corrosive - A substance that causes damage by chemical action, often resulting in severe injury or destruction.
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