Question

Which one of the following statements is correct? A. A pure substance may be separated by filtration or distillation into two or more components. B. A heterogeneous mixture is also known as a solution. C. A heterogeneous mixture is composed of two or more substances in the same phase. D. The composition is uniform throughout a homogeneous mixture. E. The combination of a liquid and a solid always results in a heterogeneous mixture.

Answer 1

Answer: Option (D) is the correct answer.

Explanation:

• A pure substance is defined as the substance that is made up of only one type of atom or only one type of molecule.

For example, $Cl_{2}$ is a molecule and it is a pure substance.

Also, substances that contain two or more different element which are chemically combined in a fixed ratio by mass are known as compounds. They are also pure substances.

A pure substance can only be separated by a chemical method and not by any physical method.

• A heterogeneous mixture is defined as the mixture which contains non-uniform composition of solute particles into the solution.

For example, mud dissolved in water.

It is not necessary that two or more substance present in a heterogeneous mixture should be of same phase.

Also, it is not necessary that combination of a liquid and a solid always results in a heterogeneous mixture.

If the solid is able to dissolve completely into the liquid then it will result in a homogeneous mixture.

• Whereas a homogeneous mixture is defined as the mixture which contains uniform distribution of solute particles into the solvent.

For example, salt dissolved in water is a homogeneous mixture.

Thus, we can conclude that the statement composition is uniform throughout a homogeneous mixture, is correct.