Corrosion is a fairly simple chemical process, and people see signs of it quite frequently in their daily lives. That makes it valuable to teachers, who can use it as an example during their lessons. Since it is a simple thing, there are just a few important points that teachers need to understand when it comes to corrosion.
Corrosion generally refers to the oxidation of a metal, which makes it ideal for teaching students about redox reactions. Rust is the most common type of corrosion, and it is produced when iron oxidizes in the presence of moisture, which can be either liquid water or vapor in the air.
The chemicals that are involved in other cases of corrosion are different, but the core mechanism remains the same in most cases. That means that students who understand rust can apply the rules to other reactions fairly easily, which makes it a great starting point for teaching them about the topic.
Protection from Corrosion
Corrosion has a large economic impact on the world, so it is natural that engineers have developed ways to prevent it. Stainless steel is one of the most basic examples. It relies on the addition of other metals, such as chromium, to the ally. Those metals react with the air to create a protective layer on the surface of the metal, which prevents air and moisture from reaching the vulnerable steel.
Environmental controls can also help to prevent corrosion, simply by making sure that metals are not used in areas where they can get exposed to corrosive chemicals. Each metal corrodes under different circumstances, so preventing problems is simply a matter of matching the right material to the right environment where it will not be at any risk.
Rate of Corrosion
Teachers should make a point of learning the speed at which metals corrode under various circumstances, since it can be useful as a lab class. Students can take a sample of each metal and expose it to corrosive chemicals, while monitoring it to see how quickly the metal changes. This generally takes a long time, so it is vital that the teacher understand the rate of corrosion to make sure they pick materials and conditions that will produce good results at a reasonable speed.
It is always good to make sure that students understand why a topic matters. In the case of corrosion, that is the economic cost of replacing corroded structures, along with the risks associated with using damaged ones. A good understanding of the economic factors will put the lesson in context and help them to understand hy people have spent so much time studying the topic.