Question

Iron objects (E--0.44 V) such as storage tanks and underground pipelines can be protected from corrosion by connecting them through a wire to a piece of

O Ag. E-0.7996 V
O Sn. E-0.1375 v
O Cu. E-0.34 V
O Mg. E-2.372 V
O Pb. E-0.1263 V

Answer 1

To protect an iron object from corrosion, another metal that is more likely to oxidize can be sacrificed. This method employs a process known as a galvanic cell, creating a connection between the iron object and this sacrificial metal.

The principle applied in this method is that the metal with the most negative reduction potential will be the first one to oxidize. In other words, this metal will lose electrons preferentially, thus protecting the iron object from oxidation or corrosion.

Given the materials in the list and their reduction potentials, we have Ag (E-0.7996 V), Sn (E-0.1375 V), Cu (E-0.34 V), Mg (E-2.372 V), and Pb (E-0.1263 V).

Upon comparing these values, it is observed that the most negative reduction potential is E-2.372 V, belonging to magnesium (Mg).

Therefore, the metal that should be used to protect the iron object from corrosion through the formation of a galvanic cell is magnesium (Mg).