Simple Science Projects Using Soda for Middle School Students

Middle-school students are a tough group to impress. Get through to these tweens by using goods that interest them. For most middle schoolers, that includes soda. As a teacher, tty simple science projects using soda to help middle-school students understand chemical changes, gas expansion and water freezing points.

Sugar in Soda

You can find out how much sugar is in a can of soda by looking at the label, but middle schoolers will get the message better if you pour a can of soda into a pot. Weigh the pot before and after the soda goes in and record the measurements. Boil the soda until all that remains is the sugar. Weigh the pot again, then calculate the difference between the full pot and the reduced pot of soda. Then subtract the weight of the pot from that figure. What remains is the weight of the sugar, about 39 grams for a can of soda. Show students the same amount in uncooked sugar.

Soda Geyser

Go outside for this fun lesson. Make sure everyone stands away from you, then drop an entire roll of Mentos candy at one time into a 2-liter bottle of diet soda, which works better for this experiment. Run away, and watch the soda bottle turn into a soda geyser. Explain that it works because water resists the expansion of bubbles in soda. By dropping in Mentos, which have tiny pitted areas that attract bubbles, you break the resistance and force a sudden increase in bubble formation, sending the liquid out of the bottle.

Super Freeze

This lesson shows how to change the point at which liquids freeze. Fill a bucket with ice until it's 3/4 full. Add a thin layer of rock salt. Insert unopened plastic soda bottles. Use a thermometer to note when the soda reaches 17 degrees. Leave soda at that temperature for 10 minutes, then remove from the ice and open the bottles. Ice crystals will form immediately. Explain that this is because the carbon dioxide in soda lowers the freezing point of water, but when the bottle is opened and carbon dioxide is released, the freezing point of the water returns to 32 degrees. Since the soda is already at 17 degrees, it freezes instantly.

Soda Shaker

Use this lesson to show why soda explodes from a shaken can, as well as how to stop it. Usually, shaking causes bubbles of carbon dioxide to line the walls of the can. Opening the can releases pressure and forces the bubbles to expand. The bubbles need to escape, so they force all of the liquid above them out of the can. Shake up a can of soda and demonstrate that fact. Then shake up a can and tap the sides before opening. The soda won't explode, because tapping makes the bubbles float to the top, where there's just a small amount of liquid blocking their exit.