Question

Rusting of an article made up of iron is called:
(A) Corrosion and it is a physical as well as chemical change
(B) Dissolution and it’s a physical change
(C) Corrosion and it is a chemical change
(D) Dissolution and it is a chemical change

Answer 1

Hint: In our day to day life we generally see that when the iron is exposed to the sunlight and water for a certain duration of time we find out that a reddish brown substance is seen. This is so because of the rusting of iron. This process of rusting of iron is called corrosion.

Complete step by step solution
In our day to day life we generally see that when the iron is exposed to the sunlight and water for a certain duration of time we found out that a reddish brown substance is seen on the surface of the iron. This is so because the rusting of iron is taking place. Now we will discuss more about rusting than how it happens and when. When this process of rusting is taking place we found out that the flaky and friable surface is obtained which gives no protection to the underlying surface and further makes it hollow.this process of rusting of iron is called corrosion. When we further discuss about the corrosion we found that this takes place as a chemical change.basically the corrosion is the process that converts a refined metal into a more chemically stable form that is oxide,hydroxide and sulphide. In technical terms we can say that this rusting is the electrochemical oxidation of metal in reaction with an oxidant such as oxygen and sulphates. As a result if we want to prevent the corrosion process we have passivation and chromate conversion which can increase metal resistance against the corrosion.

Hence, option C is correct..

Note
Rusting of iron is called corrosion as the iron gets converted into iron oxide and this is further the example of a chemical change. Hence, from here we concluded that option C is the correct one.