Question

In invar, what is the composition of iron and nickel?

(a) Fe-64%, Ni-36%

(b) Ni-68%, Fe-32%

(c) Fe-36%, Ni-64%

(d) Fe-62%, Ne-38%

I had been asked this question in an online quiz.

This key question is from Uses of Aluminium, Copper, Zinc and Iron topic in section General Principles and Processes of Isolation of Elements of Chemistry – Class 12

Answer 1

Correct answer is (a) Fe-64%, Ni-36%

Best explanation: Invar (FeNe36) is an alloy of steel which is a combination of iron and nickel. It’s percentage of the composition is 64% of Iron and 36% of Nickel. It’s mainly used for making watches. It has practically no coefficient of expansion.