Oxygen is about 20% of the earth’s atmosphere; consequently, combustion is an important reaction on this planet. It’s no wonder that scientists for centuries have been trying to arrive at a theory of why things burn. For example, Phlogiston theory was an attempt to explain combustion and was popular during the seventeenth and eighteenth centuries.
Our outreach demonstration repertoire consists of several demonstrations that illustrate combustion. One video (Basic Oxide), introduced in another blog, shows the burning of a metal, magnesium, and the result when the oxide is dissolved in water to form a basic solution (that’s what metal oxides do!). The end of the video shows the burning of butane to form carbon dioxide. Carbon dioxide, an oxide of carbon, forms an acidic solution when dissolved in water (that’s what non-metals oxides do!). The environmental consequence of non-metal oxides dissolving in water will be discussed in another posting on climate science.
Showing combustion in pure oxygen is a popular demonstration involving immersing a glowing splint into a container of oxygen and watching the splint reignite. The video below shows our version of this demo in which oxygen is formed by the catalytic decomposition of hydrogen peroxide. This demonstration is similar to the one developed by Hubert Alyea except manganese dioxide is generated in situ.