An electrochemical cell is constructed by connecting plates of iron and copper to a voltmeter and immersing the plates in separate salt solutions linked via a salt bridge. Ferroxyl indicator is added to each of the two solutions. Which of the following images best illustrates the colors of the solutions at the end of this experiment? Note that the salt bridges are omitted for clarity.
A steel vehicle is protected from rusting by spraying the exposed surface with a second metal.
What name is given to this process?
What name is given to the protective metal layer?
A steel can is protected by coating it with a layer of tin. Part of the steel surface is exposed through a scratch in the tin layer, as shown. How does the rate of rusting of the steel exposed by the scratch compare with that of uncoated steel?
Vehicle components are sometimes made of aluminum instead of steel in order to reduce the risk of oxidation.
Why is aluminum less susceptible than steel to oxidation?
Which of the following is another advantage of using aluminum instead of steel in vehicle components?
An iron surface is protected from rusting by coating it with a sacrificial metal from a salt solution. Which process is responsible for the formation of the protective layer?
The diagram illustrates an iron plate that has been protected from rusting by galvanization of the exposed surface.
Identify the material usually present in the protective coating .
When intact, how does the coating protect the iron plate?
If the coating is scratched, how does it continue to protect the iron plate?
Which of the following is the best definition of passivation?
The Statue of Liberty in New York City contains a copper skin wrapped around iron supports. Why is this design problematic?
Iron may be protected from rusting by supplying the metal with an electric current. Why does this method lower the risk of rusting?
Which of the following is the best definition of galvanic corrosion?
Which of the following is not a method for lowering the rate of rusting?
Which of the following is not a useful property in protective oil coatings for moving steel components?
A steel oil pipeline is protected via an electrical connection to a buried block of sacrificial metal. Which diagram correctly illustrates the composition of the sacrificial metal and the direction of the electrical current?
What is the main reason for preferring oil over plastic as a protective coating for a steel bicycle chain?
Which of the following is not a useful property in protective plastic coatings for moving steel components?
Which of the following metals could be used as a sacrificial coating on iron to prevent rust formation?
Based on their positions on the reactivity series, and their densities, which of the following metals would produce the lightest sacrificial coating for a lead object?
Which of the following could not be used as a sacrificial metal to prevent corrosion of tin?
Which term best describes the protective material used in cathodic protection?
Which of the following is not a useful property in sacrificial metal coatings for steel objects?