1. Cathodic protection of iron involves using another more reactive metal as a sacrificial anode. Classify each of the following metals by whether they would or would not act as a sacrificial anode to iron under standard conditions.
a. Ag
b. Mg
c. Cu
d. Pb
e. Sn
f. Zn
g. Au
1. Will act as sacrificial anode for iron
2. Will not act as sacrificial anode for iron
2. An old iron beam was coated with an unknown metal. There is a crack on the coating and it is observed that the iron is rusting at the fracture. The beam is in a structure that experiences high stress, resulting in frequent fractures to the coating. What was the old metal coating likely made of and what metal you would use to repair the fractures to avoid further corrosion? Drag each label to the appropriate target.
a. gold
b. aluminum
c. tin
1. The old coating was likely made of.
2. Would be a good choice for repairing the fracture.