Film Canister Rocket Experiment

We did this experiment during our chemical reaction unit. My kids loved it! I saw this experiment in one form or another all over the Internet. The difficult part was trying to find film canisters in our digital age. This is how I came across Science Bob's website. He has a lot of great ideas and sells film canisters!

What You Will Need:

• film canister (35mm, the white canisters work better than the black canisters with the grey lids)
• effervescent tablet (Alka-Seltzer)
• water
• plastic teaspoon
• safety goggles

What You Will Do:

You will want to do this outside. The canister lids can launch pretty high and fast!

1. Break an antacid tablet in half
2. Remove the lid from the film canister and put one teaspoon of water in the canister
3. Drop half the tablet inside the canister and quickly snap the lid back on
4. Quickly place the canister on the ground cap side down and step back...far back
5. About 10 seconds later you will hear a pop and see the canister fly into the air

If the canister does not launch in the air, wait an additional 30 seconds before examining the canister. The lid may have not been put on tightly and gas may have leaked out thus resulting in a longer wait time until the canister is launched into the air.

I had my students work in groups and they took their science notebooks outside. They were to record their observations. After they all did the initial experiment with the half tablet of Alka-Seltzer and one teaspoon of water, I asked my the following questions (I got them from the Science Bob website):

1. How much water will give the quickest launch?
2. How much water in the canister will give the highest launch?
3. Does the size of the Alka-Seltzer tablet affect how long it takes for the canister to launch?
4. Does water temperature affect how fast the rocket launches?

 

In their groups they came up with a hypothesis and went to work. It was great seeing them try out different things and making connections to what we were learning in class. As I roamed around the discussions I heard were awesome!

 

The Science:
As the antacid tablet fizzes, carbon dioxide is released inside the canister. Pressure from the gas builds and eventually pops the lid off. The thrust, or push, of your rocket is related to how much pressure built up inside the canister before the top popped off.

Check out this GREAT video where Science Bob and Jimmey Kimmel launch over 1,000 film canisters!