Question

Which one of the following is correct?
A.Rusting will take place in absence of water
B.Rusting will take place in absence of air
C.Rusting will not place in the presence of air and water
D.None of these

Answer 1

Hint:
Rusting is caused by the oxygen and water. The oxygen and water are the essential things required for rusting. Thus, rusting takes place in the presence of both air and water.

Complete step by step answer:
The process of formation of rust or the formation of iron oxides on the surface of iron is called Rusting. This is formed when the redox reaction takes place between air and iron in the presence of water. This phenomenon is a great example of the corrosion of metals, where the surfaces of metals are degraded into more chemically stable oxides. Thus, the oxygen atoms bond with iron atoms which results in the formation of iron oxides. This makes the bonds of atoms of iron weak.
The factors which affects the rusting of iron are:
-Moisture
-If the pH of the environment of the metal is low, then the rusting is quickened.
-Salt has ions which makes the rusting process quick through electrochemical reactions.
-When the iron is impure it rusts quickly as compared to the pure iron.
 As we have already read that how rusting takes place, what are the factors which affect rusting and why oxygen and water are required for the rusting process then, we can easily conclude that rusting takes place in the presence of water and air both.
Therefore, option D is the correct answer.

Note:
The rusting of iron results in the increase of oxidation state of iron which makes the electrons of iron lose. Rust is mostly made up of two different oxides of iron that vary in the oxidation state of the iron atom.
The iron atom gives electrons when exposed to oxygen because oxygen is a good oxidizing agent and iron is the reducing agent.