Hot water expands so it is less dense than room temperature water. Cold water contracts so it is more dense than room temperature water. The red hot water rises and the blue cold water sinks.
This demo uses a stove made out of aluminum cans that can be lit using knowledge of vapor pressure. When the acetone surrounding the stove is lit, the acetone in the stove boils, releasing vapors that are then lit on fire.
CH3OCH3 + 3O2 → 2CO2 + 3H2O
Potassium chlorate is such a strong oxidizer that when a gummy bear, which is mostly sugar, is placed into it, the sugar is oxidized violently producing noise and a flame. This demo can be used to discuss strong oxidizers as well as how much energy is in sugar.
This demo uses sodium hydroxide to plate Zn on the surface of a copper penny, making it appear silver in color. Zinc is oxidized in sodium hydroxide. The remaining electroplating process is not fully understood. The silvery penny can be heated to melt the zinc and copper together, creating a gold colored alloy.
This demo makes use of the catalytic decomposition of hydrogen peroxide to produce a column of steam out of a flask, that looks like a genie coming out of a bottle.
2H2O2 → 2H2O + O2, KI is a catalyst
Hydrogen peroxide is decomposed quickly in liquid soap with the help of a catalyst to create a large volume of foam that grows out of a graduated cylinder. The soap bubbles contain oxygen.
2H2O2 → 2H2O + O2, KI is a catalyst
When electricity is passed through a pickle, it is conducted through Na+ and the Cl- ions that are present in the pickle. The electricity excites the electrons to a higher energy state, and when the fall back to ground state they emit a yellow/orange light.
Universal indicator goes from red (pH 4) to violet (pH10) as the pH of a substance changes. Adding NaOH to water starts the solution off at pH 8-9 (blue). When dry ice is added to water it forms carbonic acid, and lowers the pH, which is the reason for the color changes. The “fog” that we see is condensed water vapor though, not carbon dioxide gas.
This demo uses acid base chemistry and an indicator to make an ink that will appear or disappear depending on the solution added to it. Phenolphthalein, which is clear, reacts with a base, and then turns pink.
Diet soda contains artificial sweeteners while regular soda has sugar in it. Artificial sweeteners are so sweet so only a small amount is needed, where as much more sugar is needed to achieve the same sweetness. Because regular soda has more mass in the same size can, it is more dense than the diet soda.