Which of the following statements concerning corrosion is (are) true ? For the false statements, correct them. a. Corrosion is an example of an electrolytic process. b. Corrosion of steel involves the reduction of iron coupled with the oxidation of oxygen. c. Steel rusts more easily in the dry (arid) Southwest states than in the humid Midwest states. d. Salting roads in the winter has the added benefit of hindering the corrosion of steel. e. The key to cathodic protection is to connect via a wire a metal more easily oxidized than iron to the steel surface to be protected.

Interpretation:

The authenticity of the given statements is to be determined.

Concept introduction:

The process of conversion of metal to its more stable chemical form like Hydroxide, Oxide or Sulphide is known as corrosion. Corrosion in case of Iron is known as rusting. The process of corrosion leads to the destruction of the metal.

To determine: The authentication of the given statement, “Corrosion is an example of an electrolytic process”.

The given statement is correct.

The process of corrosion in metals is basically an electrochemical process. It involves the half-cell reactions. Both the oxidation and reduction process takes place on the surface of the metal but at different locations. It consists of cathodic and anodic region and the flow of electrons occur from one region to another. Presence of water or moisture is essential for the transport of ions.

Take the example of a droplet of water and the transfer of electrons occurs from Iron to the droplet that leads to the reduction of Oxygen molecule. Thus, the Iron acts as the anode. The reactions taking place are as follows,

Fe(s)→Fe2+(aq)+2e−O2(g)+2H2O(l)+4e−→4OH

Interpretation:

The authenticity of the given statements is to be determined.

Concept introduction:

The process of conversion of metal to its more stable chemical form like Hydroxide, Oxide or Sulphide is known as corrosion. Corrosion in case of Iron is known as rusting. The process of corrosion leads to the destruction of the metal.

To determine: The authentication of the given statement, “Corrosion of steel involves the reduction of Iron coupled with the oxidation of oxygen”.

The given statement is incorrect.

Interpretation:

The authenticity of the given statements is to be determined.

Concept introduction:

The process of conversion of metal to its more stable chemical form like Hydroxide, Oxide or Sulphide is known as corrosion. Corrosion in case of Iron is known as rusting. The process of corrosion leads to the destruction of the metal.

To determine: The authentication of the given statement, “Steel rusts more easily in the dry (arid) Southwest states than in the humid Midwest states”.

The given statement is incorrect.

Interpretation:

The authenticity of the given statements is to be determined.

Concept introduction:

The process of conversion of metal to its more stable chemical form like Hydroxide, Oxide or Sulphide is known as corrosion. Corrosion in case of Iron is known as rusting. The process of corrosion leads to the destruction of the metal.

To determine: The authentication of the given statement, “Salting roads in the winter has the added benefit of hindering the corrosion of steel”.

The given statement is incorrect.

Interpretation:

The authenticity of the given statements is to be determined.

Concept introduction:

The process of conversion of metal to its more stable chemical form like Hydroxide, Oxide or Sulphide is known as corrosion. Corrosion in case of Iron is known as rusting. The process of corrosion leads to the destruction of the metal.

To determine: The authentication of the given statement, “The key to cathodic protection is to connect via a wire a metal more easily oxidized than Iron to the steel surface to be protected”.

The given statement is correct.