Why is O₂ necessary for rusting?

Oxygen is necessary for rusting because it reacts with iron to form iron oxide (rust). The reaction requires both oxygen and water, where oxygen in the air reacts with iron in the presence of moisture to create rust.

Related Questions:

  1. Choose Arrhenius acids from the following compounds: HF, NH₃, H₂SO₄, SO₂, H₂S, H₂O
  2. Which salt is formed when HCl reacts with BaCO₃?
  3. How will you justify that H₂SO₄ is a Bronsted-Lowry acid?
  4. Define oxidation in terms of electrons. Give an example.
  5. Define reduction in terms of loss or gain of oxygen or hydrogen. Give an example.
  6. What is the difference between valency and oxidation state?
  7. Differentiate between oxidizing and reducing agents.
  8. Differentiate between strong and weak electrolytes.
  9. How is electroplating of tin on steel carried out?
  10. Why is steel plated with nickel before the electroplating of chromium?
  11. How can you explain that the following reaction is oxidation in terms of increase of oxidation number?
  12. How can you prove with an example that conversion of an ion to an atom is an oxidation process?
  13. Why does the anode carry a negative charge in a galvanic cell but a positive charge in an electrolytic cell? Justify with comments.
  14. Where do the electrons flow from the Zn electrode in Daniel’s cell?
  15. What happens at the cathode in a galvanic cell?
  16. Which solution is used as an electrolyte in Nelson’s cell?
  17. Name the by-products produced in Nelson’s cell.
  18. Why is galvanizing done?
  19. Why is an iron grill painted frequently?
  20. How does calcium metal react with dilute H₂SO₄?