DISCOVER

# Coke & Alka-Seltzer for Science Projects

Updated November 21, 2016

Science projects are fun and exciting ways to study basic scientific principles. Whether performed in a classroom lab, at home or as part of a science fair, a science project allows students to develop and test their own hypotheses for a greater understanding of the scientific method. Science projects can use common household items, and you can use Coke and Alka-Seltzer in multiple ways.

## Rocketry

Students can explore basic rocketry using film canisters, Alka-Seltzer and Coca-Cola. First, the students should build three paper rockets using cardboard or construction paper. Fold the paper to create a conical nose and tape it to the lid of three film canisters. The students will create a build-up of carbon dioxide by using either Alka-Seltzer and water or by shaking a canister filled with Coke. They should hypothesise which type of rocket will travel the farthest, then fill and launch the rockets one by one. First, place some water in a film canister, then add the Alka-Seltzer and close the lid. Measure how far the rocket travels and for how long to determine its speed. Create the second rocket by putting some Coke in a film canister and then closing the lid and shaking vigorously. Again, measure how far it travels and for how long. Third, repeat the first rocket using Coke instead of water. Analyse what combination makes for the best rocket.

## Rate of Reaction

Alka-Seltzer reacts with water to dissolve, creating carbon dioxide. Students studying rate of reaction can practice dissolving one Alka-Seltzer tab in 236ml. of water, then 227gr. of milk, then 227gr. of Coke. They should time how long it takes the tablet to dissolve in each liquid and hypothesise in advance which liquid will react the fastest. After completing the experiment, they can discuss why the Alka-Seltzer dissolved at different rates and whether their hypothesis was correct.

## Neutralising Acids

Alka-Seltzer works as an antacid to neutralise acids, and Coke contains acid. Students studying acids and bases can theorise how much Alka-Seltzer is required to neutralise the acid in Coke. They should first use litmus paper to test the initial pH of a can of Coke and then slowly add small amounts of Alka-Seltzer, testing the acidity after each addition. Students can continue to experiment to see if Diet Coke or other sodas are more or less acidic to start with and, if so, if they require more or less Alka-Seltzer to neutralise their acidity.

## Do It Yourself

Students studying formulas for creating their own substances may experiment with creating their own Coke or Alka-Seltzer. Students can research recipes for Coke and other soft drinks and create their own version, performing taste-tests to see if they can create a version of Coke that passes for the real thing. They can also experiment with combining two of the main ingredients in Alka-Seltzer, citric acid and sodium bicarbonate, to create their own Alka-Seltzer. Students can then test if it dissolves as quickly as Alka-Seltzer and whether it neutralises acids, and draw conclusions about the benefits and drawbacks of homemade Alka-Seltzer.