Question

Identify the correct statement:
A. Corrosion of iron can be minimized by forming a contact with another metal with a higher reduction potential
B. Iron corrodes in oxygen free water
C. Corrosion of iron can be minimized by forming an impermeable barrier at its surface
D. Iron corrodes more rapidly in salt water because its electrochemical potential is higher

Answer 1

Hint: Corrosion of iron takes place due to the contact of iron surface with oxygen and water. This corrosion can be prevented by breaking this contact.

Complete step by step answer:
Corrosion of iron is the formation of a reddish brown oxide on the iron surface which is also called rust. Rusting is a common term for corrosion. Many metals undergo rusting but the resulting oxides are not commonly called rust. Rust does not provide any protection to the iron present inside.

Going through every option one by one we will find the correct option.
A. The first statement says that “corrosion of iron can be minimized by forming a contact with another metal with a higher reduction potential.” This statement is incorrect as we cannot use a metal with higher reduction potential as due to such metal iron will definitely corrode.
B. The second statement states that “Iron corrodes in oxygen free water.” This statement is also incorrect as corrosion cannot occur without oxygen. This is because when corrosion takes place, iron oxide is formed. If no oxygen is present then corrosion will not take place. So, this statement is also incorrect.
C. The third statement says that “corrosion of iron can be minimized by forming an impermeable barrier at its surface.” This statement is correct because by forming a barrier on iron the iron surface will not come in contact with water or air and therefore it will not erode.
D. The fourth statement states that “Iron corrodes more rapidly in salt water because its electrochemical potential is higher”. This statement is also wrong because there is no correlation between electrochemical potential of salt and corrosion. So, this statement is also incorrect.

From the above information we get to know that the correct answer is option C.

Note:
There are various ways in which corrosion can be prevented which are Galvanization, cathodic protection, production of rust-resistant alloys, coatings and painting etc.