Final answer:
The steel was coated with zinc to provide both prophylactic protection and cathodic protection, preventing it from corroding by ensuring that zinc oxidizes first before the steel.
Step-by-step explanation:
The steel produced at the plant had to be coated with zinc for a couple of reasons, which revolve around protecting the steel from corrosion. The coating serves as prophylactic protection, which means it protects the steel from reacting with oxygen in the air and rusting. In addition to this, the zinc coating offers cathodic protection. This means when the zinc is exposed to the environment, it will oxidize in place of the steel, corroding first before the underlying steel begins to corrode. The chemical reaction that takes place (Zn(s)+Fe²+ (aq) → Zn²+ (aq) +Fe(s)) underlines the process by which zinc plays the role of a sacrificial anode to give the steel this level of protection.