Question

1.Fresh sea water is referred to as impure because? a. it contains only oxygen b. it contains aquatic animals c. it contains aquatic plants d. it contains dissolved salts
2. Pure substance contain only one type of
a. mixture b. density c. matter d. mass
3. What is the best way to distinguish a pure substance from mixture?
a. through smelling
b. through tasting
c. through observing the physical properties
d. through determining the boiling point​

Answer 1

Answer:

1. it contains dissolved salts

2. mixture

3. through determining the boiling point​

Explanation:

Answer 2

The questions are answered below:

1. Fresh seawater is referred to as impure because d. it contains dissolved salts.

• Dissolved salts make the water impure. This is because salt water is a mixture and not a pure substance.
• Salt can be separated from water by evaporation.
• Thus, fresh seawater which has many dissolved salts is considered impure.

2. Pure substances contain only one type of b. density.

• A pure substance is one in which the composition is uniform. Hence, both elements, as well as compounds, are considered pure substances.
• As compounds are also included in pure substances, they may have more than one type of matter.
• But, a compound has a fixed proportion of elements, hence its density will be the same throughout.

3. The best way to distinguish a pure substance from a mixture is d. through determining the boiling point​.

• A pure substance will have a sharp boiling point while a mixture does not have a sharp boiling point.
• Thus, it can be used to distinguish a pure substance from a mixture.