Corrosion

• What is corrosion?

  Corrosion is the reaction of metals with substances.
• How do some metals react in their environment?

  They react with substances and weaken themselves.
• Which metal corrodes much more than aluminum?

  Iron and steel corrode much more than aluminum.
• What happens during corrosion?

  Metals react with substances and are gradually destroyed.
• What is rust?

  Rust is the corrosion of iron.
• What is required for iron to rust?

  Iron needs contact with both oxygen and water.
• What is the compound formed when iron rusts?

  Hydrated iron(III) oxide is formed.
• What is the equation for the formation of hydrated iron(III) oxide?

  Iron + oxygen + water → hydrated iron(III) oxide
• Where does corrosion occur on a material?

  Corrosion occurs on the surface exposed to air.
• What is the nature of rust?

  Rust is a soft, crumbly solid.
• What happens to iron in an object over time due to rust?

  All iron in the object eventually corrodes away.
• Does aluminum corrode when exposed to air?

  Yes, aluminum also corrodes when exposed to air.
• How does aluminum corrosion differ from iron corrosion?

  Aluminum forms a protective layer, unlike iron.
• Why does aluminum not flake away like iron?

  Aluminum forms a protective oxide layer that prevents further corrosion.
• What does the protective layer of aluminum do?

  It stops further reactions from taking place.
• What are the two main ways to prevent rusting?

  Use barriers or apply protective coatings.
• What are the main factors that contribute to rusting of iron?

  • Presence of oxygen
  • Presence of water
  • Exposure to air
• What can be done to prevent rusting of iron?

  1. Apply protective coatings (paint, oil)
  2. Use stainless steel or galvanized iron
  3. Keep iron dry and away from moisture
• What is the difference between rust and corrosion of other metals?

  • Rust specifically refers to iron corrosion.
  • Other metals may corrode differently.
• How does the presence of water affect rusting?

  • Water facilitates the reaction between iron and oxygen.
  • It accelerates the corrosion process.
• What role does calcium chloride play in preventing rust?

  • It absorbs water from the air.
  • It helps keep iron dry and prevents rust.
• What happens when iron is placed in boiling water?

  • It will not rust due to the removal of oxygen.
  • The boiling water stops air from getting in.
• What is the significance of the protective layer formed by aluminum oxide?

  • It prevents further corrosion.
  • It protects the underlying aluminum from damage.
• What happens to iron in a boiling tube with just air?

  It won't rust.
• How can calcium chloride be used in relation to water?

  It can absorb water from the air.
• What happens if you put an iron nail in a boiling tube with air and water?

  It will rust.
• What are the two main ways to prevent rusting?

  1. Coating the iron with a barrier

  • Paint or plastic coating
  • Electroplating with metals

  1. Sacrificial method

  • Using a more reactive metal
  • Zinc or magnesium as sacrificial anodes
• What is the obvious way to prevent rusting of iron?

  Coat the iron with a barrier.
• How can you coat iron to prevent rusting?

  By painting or using plastic coating.
• What is electroplating used for in rust prevention?

  It uses a more reactive metal to protect iron.
• What is the sacrificial method in rust prevention?

  Using a more reactive metal to protect iron.
• What happens if the zinc layer is scratched?

  The zinc will still protect the iron.
• How is oiling or greasing used in rust prevention?

  It is used when moving parts are involved.
• What is the sacrificial method's alternative name?

  The sacrificial metal method.
• What is the significance of the sacrificial method?

  It prevents rusting by using a reactive metal.
• What is the main purpose of the sacrificial method?

  To prevent rusting of iron.
• How do galvanizing and sacrificial methods differ in rust prevention?

  Galvanizing coats iron, sacrificial uses another metal.
• What is the role of water and oxygen in rusting?

  They react with iron to cause rust.
• What is the chemical process of rusting primarily caused by?

  Water and oxygen reacting with iron.
• What is the effect of galvanizing on iron nails?

  It protects them from rusting.