Separation.

Question 1

What is a mixture?

Answer 1

A substance made up of 2 or more substances physically put together e.g. water + salt and sand + water.

Question 2

Define filtration.

Answer 2

Filtration is a process that is used to separate liquids from insoluble substances.

Question 3

Where is filtration mainly used?

Answer 3

Filtration is mainly used in the large-scale treatment of water in towns and cities.

Question 4

For Figure 7.1.1 page 96, explain how the suspensions and dirt will be removed?

Answer 4

The combination of rocks, coarse sand, charcoal, and fine sand acts as a filter paper and will remove all suspension and dirt from the water.
However, this water is not safe to drink.

Question 5

Water intended for human consumption should be safe, meaning what exactly?

Answer 5

Water intended for human consumption should be safe, meaning it should be free from pathogens and harmful chemical substances.

Question 6

The major steps in a typical water purification system comprise one or more of the following measures:?

Answer 6

The major steps in a typical water purification system comprise one or more of the following measures:

• Storage.
• Filtration.
• Disinfection.

Question 7

The major steps in water treatment are:?

Answer 7

• Sedimentation.
• Filtration.
• Disinfection.

Question 8

Describe sedimentation.

Answer 8

Heavy particles settle at the bottom of the tank.

Question 9

Describe filtration.

Answer 9

Water flows through sand and charcoal to remove insoluble particles.

Question 10

Describe disinfection.

Answer 10

Chlorine is bubbled through water to kill pathogens.

Question 11

What are pathogens?

Answer 11

Pathogens are tiny living organisms, such as bacteria or viruses, which cause disease.

Question 12

Four separation methods are?

Answer 12

Four separation methods are evaporation, filtration, winnowing, and magnetism.

Question 13

Describe winnowing.

Answer 13

Winnowing is a technique used to separate substances of different densities.

Question 14

Name two applications of winnowing.

Answer 14

• Separate husks from seeds.

- Separate groundnuts and shells.

Question 15

What is chlorination?

Answer 15

Chlorination is the process of adding chlorine to drinking water to kill parasites, bacteria, and viruses.

Question 16

Why do we use winnowing to separate the seeds from the husks?

Answer 16

We use winnowing to separate the seeds from the husks because the seeds have higher densities than the husks.

Question 17

Describe magnetism.

Answer 17

We can use a magnet to separate non-magnetic materials from magnetic materials.

Question 18

Why do grinding mills use magnets?

Answer 18

Grinding mills use magnets to protect their sieves from metallic objects.

Question 19

Name three applications of magnetism.

Answer 19

• Grinding mills use magnets to protect their sieves from iron objects.
• Scrapyards.
• Mining industry.

Question 20

Name two applications of evaporation.

Answer 20

• Sugar production.

- Production of ammonia nitrate fertilizer.

Question 21

Name one application of filtration.

Answer 21

• Water treatment plant.

Question 22

How is water distilled?

Answer 22

Water is distilled through evaporation and condensation.

Question 23

What is produced during distillation?

Answer 23

Pure alcohol.

Question 24

Where else does distillation take place?

Answer 24

Distillation happens naturally during the water cycle.

Question 25

For the ethanol and water separation experiment, which one is collected first?

Answer 25

Ethanol is collected first because it boils at 78°C and water boils at 100°C.

Question 26

For Diagram 4 Chemistry Book, how can ethanol and water be separated?

Answer 26

Ethanol and water can be separated by the method because they have different boiling points.

Question 27

How do we produce ammonia nitrate fertilizer?

Answer 27

We use evaporation to produce the crystals of ammonia nitrate fertilizer from its solution.

Question 28

How do we produce sugar?

Answer 28

The water in sugar syrup is driven out by heating, the evaporation process continues until the sugar is formed.

Question 29

Diagrams to study:

Answer 29

• Filtration in a laboratory.
• Filtration in a water plant.
• Distillation (Simple).
• Ethanol and water Separation.

Question 30

What is sedimentation?

Answer 30

Sedimentation is a physical water treatment process using gravity to remove suspended solids from water.

Question 31

For the ethanol and water separation experiment, which one is collected first?

Answer 31

Ethanol is collected first because it boils at 78°C and water boils at 100°C.