Electrochemistry - Corrosion

what are the oxidzing agents responsible for the corrosion of metals

The oxidation of the metal is usually unwanted, and the oxidizing agent is usually O2(g) in water or an ion with a higher reduction potential than the metal.

define corrosion

Corrosion is a spontaneous electrochemical process where a metal oxidizes in the presence of an oxidizing agent.

how to prevent corrosion

Preventing corrosion is often an electrolytic process in which the corrosion process is stopped

what are the electrolytic processes to stop corrosion

(1) Excluding the oxidizing agent from the metal by painting or plating the metal with inert material such as gold and silver.

(2) Cathodic protection

what is cathodic protection?

Attaching a metal with a HIGHER oxidation potential (stronger reducing agent) than the metal to be protected.

eg. oxidation of Zn to protect iron pipes

- In this case, since Zn (sacrificial metal) has the HIGHER oxidation potential, it will oxidize rather than Fe.

-As it oxidizes, the iron becomes negatively charged and is further protected from corrosion.

what are some applications of corrosion prevention

1. galvanized nails (iron nails covered by zinc)

2. Zn/Mg bar attached to bottom of ships/boats