Determine whether each of the descriptions of matter describes a heterogeneous mixture, a homogeneous mixture, or a pure substance.

a. two substances present; two phases present

b. two substances present; one phase present

c. one substance present; one phase present

d. one substance present; two phases present

Answer: a. two substances present; two phases present : Heterogeneous mixture

b. two substances present; one phase present : Homogeneous mixture

c. one substance present; one phase present : pure substance.

d. one substance present; two phases present: Heterogeneous mixture

Explanation:

A pure substance is a substance which contains definite composition of only one type of component. Hence, it cannot be separated by physical means.

Mixture is a substance which contains two or more than two types of components and they can be separated by physical means as well.

Homogeneous mixtures: It is a mixture that has uniform composition throughout the solution and the particle size or shapes are not different. There is no physical boundary between the dispersed phase and dispersion medium.

Heterogeneous mixtures: It is a mixture that has non-uniform composition throughout the solution and the particle size or shapes are also different. There is a physical boundary between the dispersed phase and dispersion medium.