Butane Rocket Engine (How Rocket Engines Work)

Objective

In this experiment, you’ll explore how a simple rocket engine works by creating a reaction between water and butane. You’ll see how different combinations and reactions produce an exciting launch!

Overview

The goal is to mix various ratios of water and butane in plastic bottles to observe how the reaction changes depending on the mixture and water temperature. We’ll test how these factors affect the "rocket's" lift-off.

1. 3 Plastic Water Bottles
2. Butane Fuel
3. Gloves
4. Safety Glasses
5. Knife or Scissors (optional)

Predictions

1. How might this experiment relate to how real rocket engines work?
2. How do you think the water-to-butane ratio will affect the experiment? How might similar ratios impact rocket engines?
3. How do you think the water temperature will impact the reaction and launch success?

1. Fill three water bottles ¾ full, each with a different water temperature:
2. Room temperature
3. Cold (but not frozen)
4. Hot (but not boiling)

Wear gloves and safety glasses during this step!

1. To add butane, you can:
2. Hold down the nozzle of the butane can with pliers or scissors and release it into the bottle for about 15 seconds.
3. Alternatively, pierce a small hole in the lid just big enough for the butane nozzle. Insert the nozzle through the hole and press for about 15 seconds.

1. Once the water and butane are in the bottle, make sure the lid is off and you’re in an open outdoor area.
2. Flip the bottle upside down, and watch as it takes off!

Experiments

Trial 1: Changing Ratios

1. Experiment with different water-to-butane ratios to see how they impact the launch.

Reflection Questions

1. How did changing the ratios affect the reaction? Why do you think the outcome changed?
2. How did the different temperatures impact the launch? Why do you think it did or didn’t change?
3. Based on what you observed, how do you think this experiment relates to real rocket engines?

Conclusion

Write a brief conclusion explaining what you learned. Did your predictions match your results? Did this experiment change your understanding of how rocket engines work? What surprised you the most?

Answers to Key Questions

1. Why is water temperature important?
2. Water temperature matters because a higher temperature impacts how it reacts with the cold butane. Colder water can reduce the strength of the reaction, possibly causing a failed launch.
3. Why is the ratio important?
4. The right water-to-butane ratio is essential. Too much water means less gas is generated, while too much butane leaves little water to produce gas. The right balance allows the reaction to produce enough force to propel the bottle.
5. How does this experiment relate to rocket engines?
6. Rocket engines mix fuel and oxygen, igniting them to create thrust. In this experiment, the water and butane serve as a substitute for fuel and oxidizer. By flipping the bottle, you trigger the reaction, propelling the bottle in a way similar to how rocket fuel powers a launch.