Mythbusters - Alkali Metal Mayhem
In this episode of Mythbusters, they debunk a Braniac video (viewable on Youtube) that demonstrates an explosion produced by dropping cesium into a bathtub of water that is powerful enough to actually crack the bathtub. As they perform the experiment, the Mythbusters illustrate two types of chemical reactions. First, dropping an alkali metal in water results in a single-replacement reaction, releasing hydrogen gas. The hydrogen gas then reacts with oxygen in a synthesis reaction, forming water and releasing a lot of energy in the form of heat and light. This is also a good video to introduce the idea of the periodic law -- the alkali metals will react more violently with water as you move further down the group.
Episode: Season 6, episode 13 "Viewer Special Threequel".
Essential Concepts: Chemical reactions, single-replacement reactions, synthesis reactions, alkali metals, periodic law.
Answer key: Included in the chemistry instructor resources subscription. Click here for details.