Question

Constantan is an industrial alloy consisting of $60\%$ copper and $40\%$ nickel. It is an example of a:
A) Catalyst
B) Solid solution
C) Solid – solid reaction
D) Chemical reaction

Answer 1

Hint We know that alloys are the mixture of metals in which metal elements are combined with precision to obtain the required properties of the metal. Alloys are generally metallic in nature. By combining different metals, the metal’s properties are improved which offers high resistance to oxidation and mechanical strength.

Complete step by step answer:
We know that alloys are generally a uniform mixture of substances in solid form.
Constantan is a copper – nickel alloy also known as eureka, advance and ferry and we already know that it consists of $60\%$ copper and $40\%$ nickel.
Constantan then must be a solid solution as solid solutions often consist of two or more types of atoms or molecules that share a crystal lattice.
Constantan has a number of special characteristics due to which it is known as the most versatile alloy that is available. Its characteristics are:
1. High specific heat resistance
2. Negligible temperature coefficients
3. Easily ductile
4. Resistant to atmospheric corrosion
5. Can be easily soldered and molded.

Therefore, option (C) is correct.

Note: Constantan is generally used for making standard resistance coils as they possess high resistivity and low temperature coefficient of resistance. Also, alloys are an example of a true solution which is a homogenous mixture of two or more substances in which the substance dissolved in the solvent has the particle size of less than $1nm$.