【Daily Question】Theoretical Foundation 2020.09.06
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Multiple-choice question: To protect ships from corrosion by seawater, which metal can be used as an anodic sacrificial material? A. Zn B. Na C. Cu D. Pb Answer: A Hint: Extra rewards will be given to those who can explain the solution process; the answer can be found in the response
Answer A: According to the electrode principle of an electrolytic cell, any metal that is more reactive than iron will do
A: The electrode principle of the electrolytic cell. Zn is more reactive than Fe and can be used as a metal to be sacrificed at the anode.
A. Zinc is added to ships to protect them from corrosion by using the sacrificial anode protection method. Since zinc is more reactive than iron, it absorbs positive charges in seawater and turns into zinc ions; zinc acts as the anode, while the ship’s hull, which is made of steel, absorbs the positive charges from the zinc plate and releases hydrogen into the seawater. The presence of these positive charges prevents the ship’s hull from corroding into iron ions. Thus, adding zinc to ships provides sacrificial anode protection.