Question

Cathodic protection of iron involves using another more reactivemetal as a sacrificial anode. Classify each of thefollowing metals by whether they would or would not act as asacrificial anode to iron.

a. Sn
b. Cu
c. Zn
d. Au
e. Pb
f. Ag
g. Mg



An old iron beam was coated with an unknown metal. There is a crackon the coating and it is observed that the iron is rusting at thefracture. 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 youwould use to repair the fractures to avoid further corrosion?

Choices: tin, aluminum, gold



1. The old coating was made of __________________.

2. __________________would be a good choice for repairing thefracture.

Answer 1

1.) zinc and aluminum

2.)

a.) The old coating was made of tin.

b.) Aluminum would be a good choice for repairing the fracture.