The starting materials used to make products are known as the raw materials.

Refers to raw materials used in chemical processes to produce other substances.

An industrial method for producing sulfuric acid by oxidising sulfur dioxide to sulfur trioxide.

A type of reaction in which energy is transferred from the reactants to the surroundings.

A substance that causes damage by chemical action, often resulting in severe injury or destruction.

Industrial equilibria: Contact Process

Chemistry

In the Rates and energy changes unit, pupils learned about how energy changes are always involved in reaction, along with a range of methods for measuring and comparing rates of reaction using properties of reactants and/or products.

Industrial chemistry

industrial method making sulfuric acid from sulfur, oxygen and water

causing severe injury, damage or destruction by chemical action

reaction in which energy is transferred from reactants to surroundings

raw materials used in chemical processes to make other substances

industrial method for making ammonia from nitrogen and hydrogen

any starting materials used to make any kind of products

Match the following terms with the correct definitions.

The feedstocks of the Contact process are:

What are the reaction conditions for step 2 of the Contact process, which is 2SO$$_2(g)$$ + O$$_2(g)$$ ⇌ 2SO$$_3(g)$$?

making sulfur dioxide, from S or Cu$$_2$$S with excess oxygen

reversible reaction between SO$$_2(g)$$ and O$$_2(g)$$ to make SO$$_3(g)$$

making oleum: SO$$_3(g)$$ + H$$_2$$SO$$_4(g)$$ →H$$_2$$SO$$_7(l)$$

H$$_2$$SO$$_7(l)$$ + H$$_2$$O$$_(l)$$ → 2H$$_2$$SO$$_4(aq)$$

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).

SO$$_2$$ becomes SO$$_3$$ without doing anything else

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

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?

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

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?

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.

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.

Making sulfuric acid in industry has environmental as well as economic implications. Which of these are environmental (positive as well as negative)?

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

All feedstocks are raw materials, but not all raw materials are feedstock. Which statements explain the difference?

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

Many chemicals, including ammonia and sulfuric acid, are found in nature but in small quantities. Which of the following statements drive industrial chemistry?

This lesson will be removed by end of Summer Term 2025.

Industrial equilibria: Contact Process

Lesson outcome

This lesson will be removed by end of Summer Term 2025.