Topic1

Question 1

Name the two mental ions responsible for causing hard water

Answer 1

1.calcium
2.magnesium

Question 2

State the difference between permanent and temporary hard water

Answer 2

Permanent hard water stays hard when and after boiled
Temporary hard water turns soft when boiled

Question 3

Name the three stages in water treatment

Answer 3

1. Sedimentation
   2.filteration
   3.chlorination

Question 4

Define desalination

Answer 4

The removal of salt from salt water

Question 5

Give a difference in the composition of permanent and temporary hard water

Answer 5

Permanent water has Sulfate and temporary has hydrocarbonate

Question 6

Give 2 advantages of living in a hard water area

Answer 6

1.can improve taste
2.preferred by bakers and brewers
4.improves cardiovascular health
5.strengthens teeth and bones

Question 7

Give 2 disadvantages of living in a hard water area

Answer 7

1. Difficult to form a lather
   2.forms scum
   3.forms limescale
   4.furs up pipes

Question 8

Define solubility

Answer 8

How much of the substance can dissolve

Question 9

Define solute

Answer 9

Solid in a solution

Question 10

Define solvent

Answer 10

Liquid in a solution

Question 11

Define solution

Answer 11

Solid dissolved in a liquid

Question 12

Define saturated

Answer 12

The max amount of a solid dissolving in a liquid

Question 13

Give 2 disadvantages of fluoridation

Answer 13

1.fluorosis
2.already in mouthwash
3.causes cancer in young boys
4.form of unconceted mass medication

Question 14

Give 2 advantages of fluoridation

Answer 14

1.prevents tooth decay
2.helps family’s when can’t afford toothpaste or mouthwash because it’s already in water

Question 15

Explain how hard water hardness can be determined using soap solution

Answer 15

Hard water would take more soap solution to form a lather

Question 16

Explain how temporary water is softened by boiling

Answer 16

The hydrogen carbonate ions are heated and undergo thermal decomposition to form carbonate

Question 17

Explain how water is softened by an ion exchange column

Answer 17

Calcium and magnesium ions are replaced by sodium ions

Question 18

Explain how water is softened by addition of washing soda

Answer 18

Washing soda (sodium carbonate ) reacts with calcium Sulfate to form calcium carbonate

Question 19

Name the four layers of the earth and if there solid or liquid

Answer 19

Crust-solid
Mantle-solid with liquid properties
Outer core-liquid
Inner core-solid

Question 20

State the percentage of the following in the atmosphere
Nitrate
Oxygen
Carbon dioxide
Noble gases
Water vapour causing acid

Answer 20

Nitrate=78%
Oxygen=21%
Carbon dioxide=0.04%
Noble gases=less than 1%
Water vapour=less than 1%

Question 21

Describe wegeners theory of continental drift

Answer 21

He thought the continents were once a super continent called pangea and over millions of years the continents split apart and drifted

Question 22

Name the gases responsible for global warming and acid rain

Answer 22

CO2 and SO2

Question 23

Explain why wegners theory was not originally believed but it is now as the theory of plate boundaries

Answer 23

Wegeners theory was not believed because he couldn’t prove why it happened and we found out about the convention currents in the mantle

Question 24

Give the three pieces of evidence for wegeners theory of continental drift

Answer 24

Similar fossil fuels
Similar rocks
Continents fit like a jigsaw

Question 25

Explain why the water vapour has decreased since the early atmosphere

Answer 25

Over time the earth cooled down and the water vapour condensed forming oceans,rivers and lakes

Question 26

Describe what occurs at the following plate boundaries Constructive Destructive Conservative

Answer 26

Constructive-2 plate boundary’s move away from each other magma rises through the gap and cools forming igneous rock Destructive-2 plate boundary collide towards each other plate boundary moves into the mantle, magma spills forming volcanos Conservative-two plates slide past each other pressure builds up and they eventually goilt forward causing earthquakes

Question 27

Explain how natural processes maintain the balance of oxygen and carbon dioxide in the atmosphere

Answer 27

Photosynthesis absorbs carbon dioxide (CO2) and releases oxygen (o2) respiration absorbs o2 and releases co2

Question 28

Explain why carbon dioxide has decreased And oxygen has increased since the early atmosphere

Answer 28

Because of the early plants they released 02 and absorbed co2

Question 29

Explain how the green house effect leads to global warming

Answer 29

Traps heat into the earth

Question 30

Explain how acid rain is formed

Answer 30

S02 reacts with water vapour causing acid rain

Question 31

How can we reduce our water use

Answer 31

Turn of taps when not needed Only put a full load of clothes in the washing machine Take shorter showers

Question 32

What is sedimentation

Answer 32

Sedimentation is the removal of large insolubles particles by letting them settle

Question 33

What is filtration

Answer 33

The removal of small soluble particles by filtering them

Question 34

What is chlorination

Answer 34

The addition of chlorine to kill bacteria

Question 35

Why is desalination not widely used

Answer 35

Because not every country had low precipitation

Question 36

How do we purify water

Answer 36

By ion exchange column or reverse osmosis

Question 37

What are the chemical tests for the following gases Oxygen Hydrogen Carbon dioxide

Answer 37

Oxygen- relight a glowing splint Hydrogen- squeaky pop test Carbon dioxide- bubble it in lime water