Genie in a Bottle
Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★★☆ Can be done by science teachers
Safety: ★★★ Only to be attempted with adequate safety procedures and trained staff
Categories: Catalysts, Chemical Reactions, Elements and Periodic Table, Science Shows
Alternative titles: Hydrogen Peroxide Genie
Summary
When manganese dioxide is added to concentrated hydrogen peroxide, it rapidly decomposes into water and oxygen gas. The escaping oxygen propels a mist of water out of the container, creating the dramatic effect of a “genie” emerging from the bottle.
Procedure
- Put on safety goggles and protective equipment.
- Pour 50–100 mL of 30% hydrogen peroxide into a 2-liter bottle (enough to cover the dimples at the base).
- Using a spatula, add a pea-sized amount of manganese dioxide catalyst into the bottle.
- Step back and observe as oxygen gas is rapidly released, carrying a plume of mist out of the bottle that looks like a genie.
- Note that the reaction is exothermic; the bottle will heat up.
Links
Genie in a Bottle - Cool Science Experiment - Sick Science!:
#SparkofScience - Genie in a Bottle - The Franklin Institute:
📄 Genie in a Bottle - Steve Spangler: https://stevespangler.com/experiments/genie-in-a-bottle/
Variations
- Use different container shapes (flask, beaker, or clear bottle) to compare the visual effect of the “genie.”
- Place the bottle against a dark backdrop for a more dramatic plume effect.
Safety Precautions
- Wear safety goggles, gloves, and a lab coat at all times.
- Handle 30% hydrogen peroxide with extreme care; it is a strong oxidizer and can burn skin or eyes.
- Avoid contact with combustible materials.
- Store hydrogen peroxide in its original container away from light and heat.
- Do not perform this demonstration without supervision in a well-ventilated area.
- The reaction is exothermic; do not touch the bottle immediately after the experiment.
Questions to Consider
- Why does manganese dioxide speed up the reaction? (It acts as a catalyst, providing a surface for the decomposition of hydrogen peroxide.)
- Why is hydrogen peroxide stored in dark bottles? (Light can decompose hydrogen peroxide into water and oxygen.)
- What makes the “genie” visible if oxygen is colorless? (The effect comes from tiny water droplets carried out of the bottle with the escaping oxygen gas.)
- What everyday uses does hydrogen peroxide have at lower concentrations? (It is commonly used as a disinfectant, cleaner, and bleaching agent.)