Summary and Exam Tips for Corrosion of Metals
Corrosion of Metals is a subtopic of Electrochemistry, which falls under the subject Science in the IB MYP curriculum. The rusting of iron is a chemical reaction involving the oxidation of iron when exposed to oxygen and water, resulting in the formation of hydrated iron(III) oxide. To prevent rusting, barrier methods such as painting, greasing, and coating with plastic are employed to keep oxygen and water away from the metal surface. Additionally, storing objects in vacuum containers can prevent oxygen exposure.
Galvanizing is a method of sacrificial protection where a more reactive metal, such as zinc, is coated on iron or steel. The zinc oxidizes first, protecting the underlying metal. This principle is also applied in making brass, where zinc is used to enhance the properties of the alloy.
Understanding these concepts is crucial for preventing metal corrosion and extending the lifespan of metal objects. Remember, rust specifically refers to iron and steel, while other metals undergo corrosion.
Exam Tips
- Rust is specific to iron and steel; use the term corroded for other metals.
- Remember the acronym OIL RIG: Oxidation Is Loss of electrons, Reduction Is Gain of electrons.
- Focus on the conditions for rusting: presence of water and oxygen.
- Be familiar with barrier methods: painting, greasing, and plastic coating.
- Understand the concept of sacrificial protection and the role of zinc in galvanizing.
