You’ve heard it and maybe even said it yourself. Creating a compelling science lesson is expensive and time consuming. Who has all that equipment needed to do experiments? You do! This month we’ve gone to our cache of videos to pull out an old favorite. A bottle of carbonated soda, a balloon, and some salt never fails to entertain and provides a lot of teachable moments.
Carbon dioxide gas is essential for life on Earth and is one of the most abundant gasses in the atmosphere. It plays a vital role in plant and animal processes, such as photosynthesis and respiration. We also use carbon dioxide in other ways. Perhaps the best example is its use to give soft drinks their fizziness.
So what happens once a soda can or bottle is opened? We hear the “swoosh” sound as the gas escapes. Does that mean it’s all escaped into the air? Gilbert Gas’s Soda Surprise will answer that science question in a dramatic way.
But that’s not all you can do with soda when it comes to science activities. Here’s a follow up to the one we just discussed. Open up several other large bottles of pop (different brands). Stretch the mouth of a balloon over the openings of the bottles. Every ten minutes, go back and look at the balloon, and observe. Eventually, you’ll find that the balloons inflate because the carbon dioxide that is dissolved in the soda pop is escaping into the balloon. See which soda loses carbon dioxide the most quickly.
According to studies, the phosphoric acid in soda pop is likely the cause of bone weakening in teenage girls. If you still want to drink soda in relative safety, you can check the levels of phosphoric acid in different types of soda pop to see which sodas are least likely to impact your bones. To do this experiment, you can use a pH meter or litmus paper to test the acidity of various types of soda pop. Remember to make a hypothesis first!
Have you heard people complain that generic bottles of soda pop just “aren’t the same" as brand name bottles? Taste test (blind tasting) several different cola brands to see if it’s really possible to taste the difference. Then try something sneaky. Pour the same soda (ideally the generic) in all the cups. Have someone taste all four and guess which is the brand name soda. This may offer an opportunity to discuss the role perception and advertising plays too!
Another fun experiment explores whether Coca-Cola® and Diet Coke® will sink or float. Check out our Fuddlebrook story The Mystery of the Floating Can and watch our video. Empty the cans and try another Fuddlebrook favorite, The Mysterious Leaning Can Investigation. This is from the book A Case of Gravity.
A final activity demonstrates the effects of Coca-Cola® on teeth and helps answer the question "does toothpaste really work?" Place two eggs in two different glasses. Pour the soda over the eggs and let them soak for 30 minutes. At the end of that time, take the eggs out of the soda and observe the appearance. Next, try to remove the discoloration from the egg using toothpaste. What conclusions can you draw? This goes along with the Quirkles book Andy Acid.
So have you changed your mind? Purchase a few cans of these popular drinks and a few other simple ingredients and enjoy a day of soda pop science!