Separations and Mixtures

Question 1

What are elements?

Answer 1

An element is a substance that cannot be broken down into simplier substances by chemical means

Question 2

What forms elements?

Answer 2

atoms

Question 3

What forms compounds?

Answer 3

elements

Question 4

What is a mixture?

Answer 4

A mixture is formed when 2 or more substances are physically combined and so can be easily separated to obtain pure substances.

Question 5

What are the 2 types of mixtures?

Answer 5

Homogeneous
Heterogeneous

Question 6

What is a homogeneous mixture?

Answer 6

Where the mixture is uniformed throughout.

Question 7

What are the types of homogeneous mixtures?

Answer 7

Solutions

Question 8

What is a solution?

Answer 8

A solution is a homogeneous mixture of a solute and a solvent.

Question 9

What is the solute?

Answer 9

The substance to be dissolved

Question 10

What is the solvent?

Answer 10

The solvent does the dissolving

Question 11

What is the meaning of aqueous?

Answer 11

Having water

Question 12

What is the meaning of non-aqueous?

Answer 12

With alcohols or other liquid

Question 13

The solution may be

Answer 13

1. Aqueous (with water as the solvent)
2. Or non-aqueous (with alcohols or other liquid as the solvent)

Question 14

What is a heterogeneous mixture?

Answer 14

A heterogeneous mixture is a mixture in which the composition is not uniform throughout the mixture.

Question 15

What method could be used to separate:

Two solids, one of which will dissolve in a particular solvent and the others will not.

For example: salt and sand

What apparatus may be used?

Answer 15

Method of separation: A fractional crystallization method could be used

Apparatus: Stirrer motor, cylinders crystallized, waterbath, stirrer

Question 16

Which method of separation would be used to separate the colored mixtures based on how soluble they are in a specific solvent?

For example: pen ink

What would the apparatus be?

Answer 16

Method of separation: A chromatography method would be used

Apparatus: glass rod, chromatography paper, ink or dye, water, beaker

Question 17

What method of separation could be used when there are two miscible liquids with different boiling points?

For example: copper sulphate dissolves in water

What would the apparatus be?

Answer 17

Method of separation: A distillation method would be used

Apparatus: thermometer, distilling flask, burner, condenser, receiving flask

Question 18

What is the meaning of miscible?

Answer 18

Liquids that mix well together with other liquids.

Question 19

What is the meaning of immiscible?

Answer 19

Liquids that don’t mix well together with other liquids.

Question 20

What is a pure substance is.

Answer 20

A single substance made of only one type of particle.

Question 21

What is an impure substance?

Answer 21

An impure substance is made up of 2 or more

Question 22

Describe 4 differences between compounds and mixtures.

Answer 22

1. A compound is a chemical combination while a mixture is a physical combination.
2. A compound cannot be easily separated while a mixture can be.
3. Compounds can be of 3 types while mixtures are mainly 3 types.
4. The melting and boiling pints of a compound are defined while a mixture’s melting and boiling points are not defined.