How Does a Soda Can Calorimeter Work?
How does a soda can calorimeter work?
Calorimetry is a scientific method that uses heat to determine the energy content of foods and chemical reactions. A calorie is a measure of the amount of energy it takes to raise 1 gram of water by one degree Celsius.
It is a measure of the amount of energy needed to change the temperature of a sample, and can be used to determine the energy content of any type of substance. For example, a cup of hot chocolate contains 3 calories. A calorie is also a measurement of the amount of energy that it takes to produce one gram of heat.
Whether or not you know the difference between a calorie and a kilocalorie, it is easy to learn about how calorimetry works by using a simple, home-built soda can calorimeter! You may want to have your students do this experiment in class to make sure they understand how it works.
How to build a calorimeter
You will need a small metal can, such as a soda can (or other food packaging can), that is empty and clean on both ends. The opening on one end should be large enough to fit a temperature-resistant glass rod into, while the other should be big enough for a thermometer.
Get a larger can, too. You will need a second metal can that is at least as large as the small can, and which has an open end as well. Any metal can will work, but a soda can is the most common.
Puncture two holes in the small can, about 1/2-inch above the open end of the can. Depending on the size of your can, these may be drilled or hammered and punctured with a skewer. Once you have made the holes, insert the rod into the holes in the small can and tape it over the top of the larger can.
Pour 50 mL of water into the small can. This will be your test solution for each trial. It is important to make sure that the same amount of water is used for each trial, since a different amount of water will cause the same amount of change in the temperature.
Place a food sample in the holder. This should be a minimum of two grams. You can use a paperclip or another similar device to hold the food sample, but you can also put a piece of aluminum foil on the top of the holder to protect the surface of your table.
Pin the food sample to one of the ends so that the food “points up.” The length of the food should be parallel to the pin. This will keep the food from falling into the can, and it will take about 10 seconds for the sample to ignite.
After a few trials, you should be able to determine the energy content of your food samples. This can be compared with the calories on your nutrition labels. You can even compare the calories to your daily recommended diet!
