How are fireworks and gunpowder made? | 14-16 years

In this directed activity related to text (DART), students discover what is behind the explosive power of fireworks. The activity provides opportunities for group discussion, role play, historical research and empathetic writing through the eyes of a fictional child worker (Alice) in a blackpowder (gunpowder) factory.

Learning objectives

Students will recognise that:

• The explosive called blackpowder, or gunpowder, is made from a mixture of chemicals.
• Making blackpowder often used to involve unpleasant working conditions.

Sequence of activities

Introduction

Introduce blackpowder as the explosive ingredient in fireworks. Explain to the students that they are going to find out more about blackpowder, or gunpowder.

Making blackpowder activity: stage 1

1. Arrange the students into groups of three or four.
2. Give each student a copy of ‘Making blackpowder’.
3. Choose one or more students to read the background material to the class.
4. Invite students to imagine what the blackpowder factory must have been like.

Making blackpowder activity: stage 2

Set up the group activity in one of the following ways:

1. Task all the groups to answer the questions as set.
2. Invite different groups to look at the text from different perspectives:
   • Working conditions.
   • Safety.
   • Scientific procedures.
   • Chemical reactions mentioned or hinted at in the text.
3. Organise groups to respond in different ways to the background material. (This strategy may require extra time to carry out additional research.) Opportunities include: 
   • Writing a dialogue between Alice and a work colleague, a member of her family or the ‘boss’, including an explanation of one or more of the processes she has to work on.
   • Designing a role play to show Alice at work to ‘act’ in front of the class.
   • Carrying out an interview with the owner of the factory, asking about the working conditions and the procedures.
   • Researching the history of blackpowder further – is it still made today? If so, how? In what ways have people’s working conditions changed?

Allow about 30 minutes for students to respond to the text and work through the questions.

Supervise as groups designate a spokesperson to feedback the results of their work to the class.

Plenary

1. Bring the groups together for a plenary.
2. Depending on the strategy used, invite student(s) to give their group’s outcome(s) to the class.
3. Ensure that the outcomes from the groups are shared, to reach a common understanding of the answers to the questions, as well as a sense of how it must have felt to be Alice.
4. Widen the discussion with further questions, such as:
   1. ‘Why was so much blackpowder needed?’
   2. ‘What happened to the blackpowder after it left the factory?’
   3. ‘How is blackpowder made today?’ – if this question has not been covered by group work.

Feedback

Collect the answer sheets. Give written feedback, emphasising the extent to which students have grasped the chemical principles behind blackpowder manufacture and understood the conditions under which it was made.

Commentary

Using this material creatively, teachers can stimulate discussion and further research.

It is as a result of hearing each other’s reactions to the text and their answers to the questions that students are exposed to a range of ideas from which they draw a consensus view. The process of discussion in groups and the evaluation of outcomes, in the plenary, promotes a sharper understanding of the ideas they explore.

Supportive written feedback deals with any remaining confusion between the story and the chemical principles and processes.

Answers

Note the spelling of sulfur as ‘sulphur’ in the text.

1. Information includes: alder and willow trees cut into 3‑foot sticks; sticks are placed in a cylinder; cylinders are placed in a furnace; wood burns partially and makes a black stick; charcoal is cooled and ground to a powder.
2. Carbon
3. The carbon would make carbon dioxide gas. This is not charcoal and would be given off into the air.
4. Carbon monoxide, 2C + O₂ → 2CO.
5. The sulfur rocks cannot be used as they are.
6. Sulfur dioxide. This is formed when sulfur burns in air, S + O₂ → SO₂.
7. For example, ‘Water is added to the grough and the soluble salts dissolve making a solution. Insoluble impurities sink to the bottom. The solution is boiled and the liquid transferred to a cooler. The solution evaporates slowly and crystallises.’
8. 75% potassium nitrate, 10% sulfur and 15% charcoal.
9. The powder will not explode.
10. She weighs out 30 pounds of nitre, 4 pounds of sulfur and 6 pounds of charcoal into a box, sets the turner and mixes these substances. When they are mixed, she puts a bag underneath the box, pulls a slide and releases the powder into the bag.
11. 40 / 22 or 0.454 x 40 = 18.16 kg.
12. Safety precautions include:
    1. Changing clothes to avoid taking blackpowder to a place where there might be a flame.
    2. Not smoking in the factory.
    3. Wearing leather‑soled shoes – metal soles may create a spark.
    4. Not going ‘between houses’ to help prevent mixing of chemicals that could explode when together.
    5. Not wearing any metal items that could create a spark.
13. Not very  there was an explosion at the factory. Other precautions could be: wearing safety goggles and protective clothing, working in more isolated conditions.
14. Points from the text are:
    • A 12 or 14 hour working day.
    • Poor pay.
    • Getting hurt, ill or injured.
    • Being beaten for falling asleep.
    • Being fined for disobeying rules.
    • Working as a young child.
    • Doing heavy labour (turning the mixing box, lifting).
    • Working with the permanent risk of explosion.
    • Inhaling toxic gases.
    • Working in a very hot environment.