CORROSION KEY TERMS AND CONCEPTS
CONCEPTS
Students will know:
· Corrosion is the breakdown or deterioration of a metal by a redox reaction.
· Most metals spontaneously corrode when exposed to oxygen and water.
· Dissolved salt allows corrosion to occur faster, but it does not cause corrosion.
· A corroding piece of iron is similar to a galvanic cell. Oxygen is reduced at the cathodic region, and iron is oxidized at the anodic region. Electrons travel through the metal from anode to cathode, while dissolved ions travel through the water to maintain neutrality.
· Corrosion prevention methods include coating with paint or a corrosion-resistant metal layer, such as galvanizing with zinc; using corrosion-resistant alloys; and using cathodic protection (with a sacrificial anode or an impressed current).
· Corrosion is the breakdown or deterioration of a metal by a redox reaction.
· Most metals spontaneously corrode when exposed to oxygen and water.
· Dissolved salt allows corrosion to occur faster, but it does not cause corrosion.
· A corroding piece of iron is similar to a galvanic cell. Oxygen is reduced at the cathodic region, and iron is oxidized at the anodic region. Electrons travel through the metal from anode to cathode, while dissolved ions travel through the water to maintain neutrality.
· Corrosion prevention methods include coating with paint or a corrosion-resistant metal layer, such as galvanizing with zinc; using corrosion-resistant alloys; and using cathodic protection (with a sacrificial anode or an impressed current).
KEY TERMS
Corrosion:
The deterioration of a metal by a redox reaction.
Galnavization:
Or galvanizing, the process in which steel is coated with a thin layer of zinc to protect the steel from corrosion.
Cathodic Protection:
A form of corrosion prevention in which electrons are continually supplied to the metal that is being protected, making the metal a cathode.
Sacrificial Anode:
A form of cathodic protection in which the oxidation of a more active metal is attached to the steel prevents the iron in the steel from being oxidized.
Impressed Current:
A form of cathodic protection in which electrons from a DC power source are pumped into the metal that is being protected.
The deterioration of a metal by a redox reaction.
Galnavization:
Or galvanizing, the process in which steel is coated with a thin layer of zinc to protect the steel from corrosion.
Cathodic Protection:
A form of corrosion prevention in which electrons are continually supplied to the metal that is being protected, making the metal a cathode.
Sacrificial Anode:
A form of cathodic protection in which the oxidation of a more active metal is attached to the steel prevents the iron in the steel from being oxidized.
Impressed Current:
A form of cathodic protection in which electrons from a DC power source are pumped into the metal that is being protected.
References
- Di Guiseppe, M., Haberer, S., Salciccioli, K., Sanader, M, Vavitsas, A. (2012) Chemistry 12. Toronto: Nelson Education Ltd.
- van Kessel, H., Jenkins, F., Davies, L., Plumb, D., Di Guiseppe, M., Lantz, O., Tompkins, D. (2003). Chemistry 12. Toronto: Thomson Canada Limited.
- http://www.wikipedia.org