The model volcano is one of the best-known science projects for young people. This project tests students' creative, artistic and scientific skills. Resulting from the correct combination of chemicals, a fake eruption occurs within the body of the molded volcano. This eruption works due to the combination of the appropriate chemicals in the correct amounts. The student can use a few combinations to produce the same effect.
Baking Soda and Vinegar
To produce an eruption with baking soda and vinegar, the student starts with two spoonfuls of baking soda in the bottom of a bottle. When the student adds 1/24 cup vinegar, the two substances react in an eruption that overflows from the bottle. What appears to be a single reaction is actually two, occurring in such quick succession that it appears to be simultaneous. The acetic acid in the vinegar reacts with the sodium bicarbonate in the baking soda, forming carbonic acid. The bubbles in the eruption result from the released carbon dioxide. The leftover liquid consists of sodium acetate and water.
Diet Cola and Scotch Mints
In the diet cola and scotch mints version of the science project volcano, a student creates a funnel with a newspaper and sticks it into the mouth of a 12-oz. bottle of diet cola. Once the funnel is in place, the student attempts to pour as many scotch mints down the funnel as quickly as possible. The more scotch mints the student gets in before the explosion, the higher the geyser will go --- some up to 10 meters. This explosion occurs because of a process called nucleation. The carbon dioxide in the soda finds nucleation sites on the scotch mints, which exist on the liquid sugar coating on the candy. These sites act as holes, or nooks and crannies, the carbon dioxide latches onto, creating a fizz that shoots out of the bottle.
Diet Soda and Salt
Diet soda and salt work in the same way as diet soda and scotch mints. Any diet soda will work, as the key to this eruption is the fact that diet soda doesn't have real sugar in it, which slows the explosive reaction. To make this project work, open a new 12-oz. bottle of diet soda. Pour 2 Tbsp. of salt down a funnel into the diet soda, the soda will erupt. Here, the carbon dioxide in the bubbles of the soda will undergo a nucleation reaction with the salt crystals just as it did with the scotch mints.
Yeast and Peroxide
A yeast-and-hydrogen-peroxide explosion occurs because yeast acts as a catalyst to the peroxide. Hydrogen is an unstable compound, decomposing to water and oxygen as soon as it's exposed. On an everyday basis under normal conditions, this decomposition would be slow and unimpressive. When you introduce the yeast, this reaction occurs suddenly and mimics an eruption. For this experiment, the student places 4 oz. of hydrogen peroxide into a bottle. The student then mixes a single packet of yeast with enough warm water to make a paste and lets it sit for five minutes. The student then pours the yeast into the bottle, and the reaction occurs instantly.
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