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Flashcards in C3: UNFINISHED Deck (70):
1

Why do geologist study rocks?

To see how Earths rocks surface has changed

2

What do geologist look at?

-They look at how rocks form
-How rocks change
-And when changes happen

3

What was the super-continent known as?

Pangea

4

Originally were was Britain located?

Near the equator

5

As volcanic lava solidifies, what rock is formed?

Igneous rock

6

The Earth's magnetic field...

changes over time.

7

How can magnetic patterns help geologist find out the Earth's movement?

The rocks are aligned with the Earth's magnetic field so geologist track the slow movement of continents.

8

What are the three most important raw materials?

Coal,Salt and Limestone

9

What started 200 years ago in the north-west of England?

Industrial Revolution

10

Where was there large deposits of coal?

Lancashire

11

Cheshire had large deposited of ...

Salt

12

Where was there large deposits of Limestone?

Peak District

13

Name 3 uses of Salt

1. In the food Industry
2. As a source of chemicals
3. To treat icy roads

14

How can salt be obtained?

1. Evaporation pools
2. mining underground salt deposits
3.Solution mining

15

Why is salt put on icy roads?

-Mixed with sand it gives the ground grip
-the salt lowers the freezing point allowing ice to melt

16

Salt extraction from sea water...

is only economical in hot climates

17

What method obtains purer salt?

Solution mining

18

What is a risk of mining rock salt and solution mining?

Subsidence

19

Why can some salt not be mined?

Half the rock salt is left for support: so subsidence don't happen

20

What do you do if you need more salt?

You import it

21

What is a risk of solution mining?

Water may leach out and contaminate water supplies

22

What is a risk of Evaporation pools?

It takes up large areas and spreads salt into the local environment, damaging habitats.

23

Why is salt used in the food industry?

for flavouring and as a preservative.

24

How does salt act as a preservative?

Higher levels of salt prevents bacteria growth

25

High blood pressure, heart failure and stroke are results of WHAT?

Too much salt intake

26

Why is salt a hazard?

Because it poses a risk to health

27

Who is in charge for carrying out a risk assessment for chemicals in food and advising the public about how food affects health?

The government Department of Health (DH) and the Department of the Environment, Food and Rural Affairs (Defra)

28

Alkalis make What change colour?

Indicators

29

Alkalis neutralise acids to make salts, what is this process called?

Neutralisation

30

Acid + Alkali =

salt + water

31

What are alkalis used for :

1. Neutralising acid soil
2. Making soap
3. Making glass

32

How was soap made in the past?

Using a mixture of potash (burnt wood) and animal fat , which is boiled

33

What was the first alkali manufactured and how?

Calcium oxide (lime) and by heating limestone (calcium carbonate) in a lime line using coal as fuel

34

Name 4 main acids

1.Hydrochloric acid
2. Nitric acid
3. Sulfuric acid
4. Phosphoric acid

35

In 1787 , what Frenchman discovered how to manufacture an alkali?

Nicholas Leblanc

36

What was the Leblanc process?

Reacting salt and limestone in heat to form sodium carbonate

37

What was the problem with the Leblanc process?

It released lots of Hydrogen chloride (an acidic, harmful gas) and solid waste called galligu (which in turn released hydrogen sulfide a toxic gas)

38

What did the better process do to the waste hydrogen chloride?

It made it useful by
-using chlorine to bleach textiles prior to dying
-and hydrochloric acid, was used as a starting material for other chemicals

39

A solution with a pH greater than 7 is known as a what?

Alkali

40

What colours does alkalis turn indicators

Blue or violet

41

Give 2 examples of a metal hydroxide

NaOH and Ca(OH)2

42

Alkalis are soluble...

Metal hydroxides and Metal carbonates

43

When metal hydroxides and metal carbonates are insoluble what are they called?

Bases

44

Hydroxide + acid =

salt + water

45

carbonate + acid =

salt + water + carbon dioxide gas

46

Why did people die from drinking water in the 19th century?

Because they got water-borne diseases like cholera and typhoid

47

What is now added to drinking water?

Chlorine

48

What is the process of added chlorine to drinking water?

Chlorination

49

Who has no choice about chlorination?

Those who use the main water supply.

50

Chlorine can react with organic materials in water supplies forming WHAT?

Disinfectant by-products (DBPs)

51

Why does the government carry on chlorination anyway?

Because the benefits outweigh the risks.

52

What is Electrolysis?

Breaking up a compound using an electric current

53

Name the products when you electrolyse brine

-Chlorine gas
-Hydrogen gas
-Sodium hydroxide solution

54

The anode is the ...

Positive electrode

55

The cathode is the...

Negative electrode

56

Why is electrolysis expensive?

Because it requires large amounts of electricity

57

Name one method to electrolyse brine continuously

The membrane cell

58

Where does chlorine form during electrolysis?

At the at the anode

59

What forms at the cathode?

Hydrogen

60

What can chlorine be used for?

In plastics like PVC

61

What can hydrogen be used for?

In margarine and as rocket fuel

62

What can sodium hydroxide be used for?

In paper recycling and refining aluminium

63

What are the risks of chlorine?

-Chlorine in products is linked to ozone depletion
-Plastics made using chlorine are non-biodegradable

64

What is a used to find out how dangerous substances are?

A risk assessment

65

What four things do you need to know to assess the level of risk of a chemical?

-how much is needed to cause harm
-how much will be used
-the chance of it escaping into the environment
-who or what it may effect

66

What does PVC contain?

Carbon, Hydrogen and Chlorine

67

What are added to PVC to make them softer?

Plasticisers

68

What are plasticised PVC used for?

Seat covers, clothing and cover electrical wires

69

What did USA and Europe ban?

Plasticised PVC in toys

70

What happens when you burn PVC?

Toxic gases including dioxins. If eaten, they can build up and cause cancer