Question

9. What is a sacrificial anode and how does it help prevent corrosion?

10. Zinc and tin are two metals that are used as a protective coating on iron: but if the protective coatings are broken exposing the iron beneath the two coatings it causes very different reactions. Using your knowledge of the reactivity of metals and redox reactions explain the differences in the corrosion reactions that occur if the metal coatings are broken.

11. A common method of rust proofing the underside of cars is spraying on a protective coating of oil annually. Explain at least one negative environmental impact of the method of corrosion protection.

Answer 1

9. What is a sacrificial anode and how does it help prevent corrosion?

Step-by-step explanation:

Sacrificial Anodes are highly active metals that are used to prevent a less active material surface from corroding. Sacrificial Anodes are created from a metal alloy with a more negative electrochemical potential than the other metal it will be used to protect. The sacrificial anode will be consumed in place of the metal it is protecting, which is why it is referred to as a "sacrificial" anode.

the positively charged zinc ions at the zinc (anode) surface react with negatively charged hydroxyl ions from the electrolyte and zinc is slowly consumed, providing sacrificial protection for the steel.thos phenomenon that prevents corrosion of the steel,i.e the cathode, is known as cathodic protection