Today I began by showing students the “Electrolysis of Water,” where electricity is used to rip water molecules apart. I showed them this experiment to illustrate how an equation can be used to describe a chemical reaction.
It’s almost like learning a new language, I told them. The chemical formulas in the equation tell you what to draw and the coefficients tell you how many to draw. The equation above can be translated into a picture, as shown below.
Believe it or not, all three of these examples (the experiment, the equation, and the picture) showed students the same thing: when you electrocute water molecules, they divide into hydrogen gas (H2) and oxygen gas (O2). After this discussion, students practiced translating the equations into pictures using the worksheet below.