Question

When a piece of magnesium is connected to an iron pipe, the iron is prevented from corroding. Which of the following is the best explanation?

Magnesium reacts with the ground water to form a protective coat on the iron pipe of Mg(OH)2.
Magnesium atoms replace the iron atoms lost when the iron corrodes.
Electrons flow from the iron through the wire to the magnesium leaving a protective coating of Fe+3 on the pipe.
When magnesium corrodes, electrons flow through the wire to the iron pipe, thus preventing the iron atoms from losing electrons.
The electric current flowing through the ground from the magnesium to the iron kills the organisms which attack and corrode the pipe.

Answer 1

The answer is "when magnesium corrodes, electrons flow through the wire to the iron pipe, thus preventing the iron atoms from losing electrons".

This is correct, because I got it right on my assignment.

Answer 2

Answer : Option D) The electric current flowing through the ground from the magnesium to the iron kills the organisms which attack and corrode the pipe.

Explanation : When we attach a piece of Mg to the iron pipe which is dipped in underground water it acts as a sacrificial anode and protects the cathode which is iron in this case. Here, the electric current produced from the sacrificial anode kills the micro-organisms that cause corrosion to the iron pipe.