Hydrogen Mini Rocket

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: Combustion, Explosions, Gases

Alternative titles: Hydrogen–Oxygen Fuel Rocket

Summary

Hydrogen and oxygen gases are produced in the lab through chemical reactions, then combined and ignited to propel a small rocket across the room. The demonstration highlights multiple types of chemical reactions: double replacement, decomposition, combustion, and synthesis.

Procedure

Generate hydrogen gas by reacting zinc with hydrochloric acid.
Generate oxygen gas by decomposing hydrogen peroxide with a catalyst such as manganese dioxide or yeast.
Collect the gases in small containers or balloons.
Mix hydrogen and oxygen in the correct proportions to form a combustible fuel mixture.
Ignite the mixture with a flame or spark to launch a small container (such as a teat pipette bulb) forward.
Observe the loud “pop” or explosive sound and the motion of the mini rocket.

Links

Making Hydrogen Fueled Mini-Rockets - Beals Science:

📄 Micro Rocket Lab - Flinn Scientific: https://www.flinnsci.com/api/library/Download/73ea6e2a619444b5b3b6eabee20a81e0?srsltid=AfmBOoqZ9uQdqUN-JeLc0yv5UTwPhRRE9e4O4456xuUTtWjvaMjwZeCk

📄 Mini Rockets - U.S. Department of Energy: https://www1.eere.energy.gov/education/pdfs/solar_minirockets.pdf

Variations

Change the ratio of hydrogen to oxygen to see which mixture produces the most powerful launch.
Try different catalysts for the hydrogen peroxide decomposition (manganese dioxide, potassium iodide, yeast).
Add fins or a cone to the mini rocket for stability.
Use electrolysis to produce the hydrogen and oxygen.

Safety Precautions

Safety goggles, gloves, and lab apron required.
Perform only under teacher supervision.
Keep ignition sources away from gas generators until ready.
Do not scale up the experiment — only small amounts of gas should be used.
Ensure the rocket is not aimed at people or breakable objects.

Questions to Consider

Which types of chemical reactions are demonstrated in this experiment? (Double replacement, decomposition, combustion, synthesis)
What is the balanced chemical equation for hydrogen combustion? (2H2 + O2 → 2H2O)
Why is the correct ratio of hydrogen to oxygen important for the rocket’s power? (Only the stoichiometric ratio ensures all reactants are used, producing the most energy.)
Why doesn’t the mixture react immediately when the gases are combined? (It requires activation energy from a flame or spark.)
How is this demonstration similar to real rocket propulsion? (Both rely on rapid combustion of fuel with an oxidizer to release energy and create thrust.)