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.

Option (D) is the correct answer.

Explanation:

For example, 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.

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.

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.