New
New
Year 11
OCR
Higher

Industrial equilibria: Contact Process

I can describe the Contact Process for the production of sulfuric acid, explain the importance of each step, and describe the conditions used.

New
New
Year 11
OCR
Higher

Industrial equilibria: Contact Process

I can describe the Contact Process for the production of sulfuric acid, explain the importance of each step, and describe the conditions used.

Lesson details

Key learning points

  1. The Contact Process involves the production of sulfur trioxide (SO₃) from sulfur dioxide (SO₂) using a catalyst.
  2. The process has three main stages: burning sulfur to produce SO₂, converting SO₂ to SO₃, then converting SO₃ to H₂SO₄.
  3. The conversion of SO₂ to SO₃ is a reversible reaction performed at 1-2 atmospheres and 450°C, using a V₂O₅ catalyst.
  4. Sulfuric acid production is energy-intensive and releases large amounts of CO₂, contributing to global emissions.
  5. 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.

Equipment

None required.

Licence

This content is © Oak National Academy Limited (2024), licensed on Open Government Licence version 3.0 except where otherwise stated. See Oak's terms & conditions (Collection 2).

Loading...

6 Questions

Q1.
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.
Correct Answer: scale, size
Q2.
Sulfuric acid is corrosive. What warning symbol would you expect to see on a flask of concentrated sulfuric acid?
An image in a quiz
Correct Answer: An image in a quiz
An image in a quiz
An image in a quiz
An image in a quiz
Q3.
A type of reaction in which energy is transferred from the reactants to the surroundings is called an reaction.
Correct Answer: exothermic
Q4.
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
Correct answer: high emissions of CO$$_2$$
Correct answer: high energy use
Correct answer: unreacted gases can be recycled
use for petroleum refinery
Q5.
All feedstocks are raw materials, but not all raw materials are feedstock. Which statements explain the difference?
Correct answer: feedstock is a subset of raw materials, used in chemical processes
raw materials are always simpler, in chemical terms, than feedstocks
Correct answer: raw materials are anything that can be used for making any product
Q6.
Many chemicals, including ammonia and sulfuric acid, are found in nature but in small quantities. Which of the following statements drive industrial chemistry?
Correct answer: a growing world population needs more food and fertilisers
Correct answer: solutions can be found for energy use and environmental impacts
the natural sources of ammonia and sulfuric acid may run out
Correct answer: there are significant economic implications from major industrial processes

6 Questions

Q1.
Match the following terms with the correct definitions.
Correct Answer:Contact process,industrial method making sulfuric acid from sulfur, oxygen and water

industrial method making sulfuric acid from sulfur, oxygen and water

Correct Answer:corrosive,causing severe injury, damage or destruction by chemical action

causing severe injury, damage or destruction by chemical action

Correct Answer:exothermic reaction,reaction in which energy is transferred from reactants to surroundings

reaction in which energy is transferred from reactants to surroundings

Correct Answer:feedstock,raw materials used in chemical processes to make other substances

raw materials used in chemical processes to make other substances

Correct Answer:Haber process,industrial method for making ammonia from nitrogen and hydrogen

industrial method for making ammonia from nitrogen and hydrogen

Correct Answer:raw materials,any starting materials used to make any kind of products

any starting materials used to make any kind of products

Q2.
The feedstocks of the Contact process are:
hydrogen
nitrogen
Correct answer: oxygen
Correct answer: sulfur
Correct answer: water
Q3.
What are the reaction conditions for step 2 of the Contact process, which is 2SO$$_2(g)$$ + O$$_2(g)$$ ⇌ 2SO$$_3(g)$$?
iron catalyst
Correct answer: pressure 1-2 atm
pressure 200 atm
Correct answer: temperature 450$$^o$$C
Correct answer: vanadium (V) oxide catalyst
Q4.
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 Cu$$_2$$S with excess oxygen
2 - reversible reaction between SO$$_2(g)$$ and O$$_2(g)$$ to make SO$$_3(g)$$
3 - making oleum: SO$$_3(g)$$ + H$$_2$$SO$$_4(g)$$ →H$$_2$$SO$$_7(l)$$
4 - H$$_2$$SO$$_7(l)$$ + H$$_2$$O$$_(l)$$ → 2H$$_2$$SO$$_4(aq)$$
Q5.
Step 1 of the Contact process, e.g. S$$_(g)$$+O$$_2(g)$$ →SO$$_2(g)$$ is an ideal set-up for step 2 where SO$$_2(g)$$ needs to become SO$$_3(g)$$. Why is this?
SO$$_2$$ becomes SO$$_3$$ without doing anything else
Correct answer: SO$$_2$$ is already mixed with O$$_2$$, ready for the next step
the reaction conditions are already ideal
the unreacted gases can be recycled in step 1
Q6.
Hypothetically, SO$$_3$$+H$$_2$$O→H$$_2$$SO$$_4$$, but this is never done. Why can we not just add sulfur trioxide to water to make sulfuric acid?
Correct answer: 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
Correct answer: the reaction is highly exothermic and creates dangerous clouds of sulfuric acid