Lab: Alka-Seltzer Rockets FOR THE TEACHER Summary In this lab, students will conduct a chemical reaction that will be used to launch a rocket. Grade Level Elementary school
Submitted by Mary Beth Neetz All Saints Central Elementary Bay City, Michigan Thanks to Dow Chemistry Teacher Summit
Objectives By the end of this lab, students should understand that mixing chemicals causes a reaction. be aware of the law of conservation of matter. be able to describe gas pressure and connect it to their observations in the experiment. be able to discuss Newton‟s Law of Motion. Chemistry Topics Chemical reactions Conservation of matter Gas pressure Time Teacher Preparation: 20 minutes Lesson: 45 minutes Materials one plastic film canister for each student 1-2 Alka-Seltzer tablet for each student warm water to fill the canisters half full for each rocket paper, 6” by 6” (you can get 4 out of one 12 x12 scrapbook piece of paper) tape, scissors, crayons to make your paper „rocket‟ Safety Always wear safety goggles when handling chemicals in the lab. Students should wash their hands thoroughly before leaving the lab. When students complete the lab, instruct them how to clean up their materials and dispose of any chemicals. Students should move away from the rocket, once the Alka-Seltzer tablet has been added and the film canister is sealed. Teacher Notes You can start the lesson by watching Bill Nye‟s Chemical Reactions Video. This DUCKSTERS site explains chemical reactions.
The type of film canister that has a lid that fits INSIDE the canister, rather than one that snaps on the outside of the rim works best. You can ask stores, but it is easiest to order them from online, from a store such as Amazon. The white/clear canisters work best! Generic Alka-Seltzer works as well as name brand. You may want to talk about the difference between this rocket experiment and real rockets. The idea that pressure from the gas exerts a force is true, but in the case of rockets, it‟s a bigger, more dangerous reaction that emits the gas, allowing the rocket to launch. The weight of the paper used to make the rocket will have an effect on how high it goes. I don‟t recommend using heavy scrapbook paper. Using colored printer paper will save time over allowing the students to color. Students may tend to put a lot of effort into the coloring that may be destroyed on the first attempt if it gets too wet. We found the highest height & best result was achieved when we used 1 teaspoon of water and 1/2 of an Alka-Seltzer tablet, but you could let the students experiment themselves to see what happens when you adjust the ratios. They could then record their findings. I would adjust the amount of Alka-Seltzer for younger children to only ¼ of a tablet. The reaction time is a little longer and the pressure is not at strong. Depending on the age and ability level of the students, the analysis questions can be done together, as a class discussion. Allowing the students to design their own experiment to try to make the rocket travel further would be a fun challenge, and could become a contest within the class. Allow all students access to the same amount of materials, but students would hopefully think about changing variables on their own (temperature of water, amount of water, amount of Alka-Seltzer, surface area of Alka-Seltzer, etc.)
Cross-Disciplinary Extensions Connect to Math Do the same reaction in a flask with a balloon on top to collect the carbon dioxide given off and have students measure the mass before and after the reaction to see that they are pretty much the same. Connect to Reading Extend the lesson with reading about Isaac Newton and the Laws of Motion. Who Was Isaac Newton? by Janet Pascal, with illustrations by Tim Foley and Nancy Harrison Connect to Writing Write a “How To” paragraph on how to make the rocket, in their own words, followed by a paragraph explaining the science behind it. Include a picture of their project. Connect to Social Studies Have students discuss how chemical reactions have changed the world in which we live.
FOR THE STUDENT Lesson Alka-Seltzer Rockets Prelab Questions Define the term chemical reaction. Objective You will be constructing a rocket that will be propelled into the air by a chemical reaction.
Safety Always wear safety goggles when handling chemicals in the lab. Wash your hands thoroughly before leaving the lab. Clean-up your materials according to your teacher’s instructions When the Alka-Seltzer tablet has been added to the film canister, move away from the rocket. Procedure 1. Cut paper into a 6” by 6” square. 2. Roll paper around the film canister. Make sure the canister is upside down at the bottom of the roll and that the lid can fit on and off easily.
3. Cut out a circle of paper for the top of the rocket. Cut 1/4 of the circle out (a triangle shape) so that it can fold into a cone, and tape to the top of your rocket.
4. Cut three triangles out of paper and tape to the bottom of the rocket. Decorate any of these pieces as you wish with crayons, markers, etc.
5. Turn the rocket upside down, fill it about halfway with some warm water. 6. Now, drop ¼, ½ or a full Alka-Seltzer tablet into the canister. 7. QUICKLY place the lid on the canister, and the rocket down (right side up), with the lid on the table. 8. Move away from the rocket. Observations Write a sentence about what you saw happen. Analysis 1. The reaction inside the canister created carbon dioxide gas. How is it possible to make a gas from a solid tablet and water? 2. Why did the lid of the canister pop off? 3. Did your rocket travel very far? What are some ideas for making your rocket travel further if you did this experiment again?
