In past experiments, you have learned about the gas carbon dioxide. For example, you may have tried blowing up a balloon with vinegar and baking soda, dissolving an egg shell or exploding a Ziplock bag.
When you add water to an Alka-Seltzer tablet, it starts a chemical reaction. The tablet dissolves, fizzes, and creates carbon dioxide gas. The reason this happens is because Alka-Seltzer tablets contain sodium bicarbonate (NaHCO3) and citric acid. When sodium bicarbonate atoms dissolve in the water, they breaks apart into separate sodium (Na+) and bicarbonate (HCO3-) ions. Then those bicarbonate ions react with the citric acid to create carbon dioxide gas. When carbon dioxide gas is contained within a film canister (or any enclosed space), the pressure increases as that gas is produced. Eventually, that pressure has to be released!
If you’ve ever used vinegar and baking soda to create a volcano, you’re seeing the very same reaction between the acid in the vinegar and the sodium bicarbonate in the baking soda that you do when you combine Alka-Seltzer and water.
Now that you understand the chemical reaction that will fuel your rocket, let’s get started!
YOU WILL NEED:
- Film canister (you should be able to find these at any location that develops film)
- Alka-Seltzer or other brand fizzing antacid tablets
- Safety goggles
Here’s what to do!
- Put on your safety goggles!
- Break the antacid tablet in half. You won’t need the whole tablet for this demonstration.
- Remove the lid from the film canister and set it aside.
- Add 1 teaspoon of water into the film canister.
- Now, you are going to have to move quickly! Place the half tablet of Alka-Seltzer into the film canister and snap the lid on tight.
6. Step back and watch! What happened?!
Within a few seconds, the lid of the film canister should have popped off. If you want to create an even bigger result, flip the canister upside down after step 5 and watch the canister fly high into the air! If you choose to try this, make sure you go outside so you don’t make a mess or hit anything with a flying film canister rocket!
What if you add more antacid to your canister? Will it fly higher? Does the amount of antacid affect the time it takes the rocket to launch?
Check out the video below. They chose to use vinegar and baking soda rather than the antacid tablet. How did they get the same result? Try it both ways and see if one works better than the other!
Do you think creating a nosecone or fins would make your rocket fly higher or straighter? Try it out!