Describe the following types of corrosion and give a practical example of each

1.pure chemical corrosion
2.pure electrochemical corrosion

See this site for #2,

http://chemwiki.ucdavis.edu/Analytical_Chemistry/Electrochemistry/Electrochemistry_7%3A_Electrochemical_Corrosion

#1 example. Fe rusts.

looking for practical example of pure chemical corrosion and electrochemical corrosion

1. Pure chemical corrosion occurs when a metal undergoes a chemical reaction with a non-metallic substance, without the influence of an external electric current. This type of corrosion typically occurs due to exposure to acids, bases, or salts.

A practical example of pure chemical corrosion is the reaction between iron and oxygen in the presence of moisture, which results in the formation of rust. When iron is exposed to moisture, it reacts with oxygen in the air to form hydrated iron(III) oxide, commonly known as rust. This reaction occurs without the presence of an external electric current and is purely a chemical reaction.

2. Pure electrochemical corrosion, also known as galvanic corrosion or bimetallic corrosion, occurs when two different metals are in contact with each other in the presence of an electrolyte. An electrolyte can be any conductive solution, such as saltwater or acidic solutions. In this type of corrosion, one metal acts as an anode (electron donor) and the other as a cathode (electron acceptor), and an electric current flows between them.

A practical example of pure electrochemical corrosion is the corrosion of a steel (iron) nail when it is exposed to a saltwater solution. If a steel nail is inserted into a piece of copper in the presence of saltwater, a galvanic cell is formed. The copper acts as a cathode, while the steel nail acts as an anode. The flow of electrons from the steel nail to the copper results in the corrosion of the nail.