Question

Which of the following is a homogeneous mixture?
(A). Milk
(B). Steel
(C). Smoke
(D). Soil

Answer 1

- Hint: The question is asking for a homogeneous mixture. So first let us know the definition, “It is a mixture in which the composition is uniform throughout the mixture. For example, the salt water is homogeneous because the dissolved salt is distributed evenly throughout the entire sample present.”

Complete step by step answer:
Let us see the options provided one by one,
Milk - It is an emulsified colloidal solution of fat globules dispersed in water-based medium. Colloids are nothing but a mixture in which the substances are regularly suspended in a fluid. Colloids are considered to be as heterogeneous mixtures. So this option is incorrect.
Steel - Steel is homogeneous, because it is an alloy (a solid mixture of different metal components). It is a homogeneous mixture of iron, carbon, nickel and other elements.
Smoke - We must know that smoke is a term used for one of the products of a fire. It is actually a collection of particles that are less than five microns in diameter and stay suspended in the air. That is why smoke is a heterogeneous mixture.
Soil - Soil is made up of a variety of substances, for example pebbles, plant matter and sand. These components remain separate in the mixture. Hence we can say soil is a heterogeneous mixture.
Therefore we can conclude that option B is the correct answer.

Note: We can easily be confused between a homogeneous mixture and a pure substance because they are both uniform in nature. The only difference is that the amount of solute in solvent can vary from one sample to another (for example, salt in salt water) but the composition of the pure substance is always the same (for example, gold).