Exploring Fire and Chemical Reactions

Introductions

A campfire is more than just a way to stay warm—it’s a chemical reaction! In this activity, Scouts will explore combustion, flame colours, and fire safety through two hands-on experiments:

1. Colourful Flames – Adding safe household chemicals to a fire to create different colours
2. DIY Fire Extinguisher – Understanding the fire triangle and using chemical reactions to put out a flame

This is a great way to learn about fire science, oxidation, and how elements react to heat.

What you'll need

• For Colourful Flames:

  • A campfire, cast-iron stove, ceramic bowl with methylated spirits, or a tea candle
  • Heat-proof gloves
  • Fire blanket and fire extinguisher
  • Metal teaspoons (one per chemical)
  • Small spray bottles (optional, for liquid application)
  • Household chemicals (use one per test):
    • Sodium chloride (table salt) – Orange flame
    • Potassium chloride (salt substitute) – Purple flame
    • Copper sulfate (fertiliser) – Blue flame
    • Magnesium sulfate (Epsom salts) – White flame
    • Borax (sodium tetraborate) – Green flame (use with safety precautions)
    • Flour or sugar – Creates quick flares or sparks

For DIY Fire Extinguisher:

• Baking soda (sodium bicarbonate)
• Vinegar
• Tealight candles
• Large glass or jar
• Aluminium foil (to protect surfaces)

Activities

Experiment 1: Colourful Flames

• Set up the fire (campfire, stove, or ceramic bowl with methylated spirits)
• Add chemicals carefully:
  • Sprinkle a teaspoon of a chosen chemical into the flames
  • Observe the colour change
  • Try different chemicals one at a time
• Alternative methods:
  • Spray bottle method – Mix a concentrated solution of the chemical in water, then spray into the flame
  • Soaked wood method – Soak sticks in chemical solutions, dry them, and then burn them

Experiment 2: DIY Fire Extinguisher

• • Light a small tealight candle
  • Mix baking soda and vinegar in a large jar – this creates carbon dioxide gas
  • Pour the gas (not the liquid) over the flame and watch it go out
  • Try using an empty jar to compare – what happens?

Change the challenge level

Easier:

• Use pre-mixed fire colourants instead of measuring chemicals
• Focus on observing the flame colours rather than mixing solutions

Harder:

• Research how different metals and compounds create specific flame colours
• Try different fire extinguishing methods (e.g., smothering, removing heat)
• Experiment with changing the size or temperature of the fire – how does it affect results?

Reflection