Ocr Chemistry- C3

Front 1

What do geologists do ?

Back 1

They explain most of the past history of the surface of the earth in terms of processes that can be observed today

Front 2

What do movements of tectonics plates mean ?

Back 2

They mean that the parts of ancient continents that now make up Britain have moved over the surface of the earth

Front 3

How do geologists use magnetic clues in rocks to track the very slow movement of the contents over the earths surface ?

Back 3

1. tectonic plates move away from each other under the sea 2. the exposed magma rises up through the sea floor

2. it solidifies to form new crust

3. the crust is then magnetised by the earths magnetic field

(the earths magnetic field swaps direction every half million years, so the rocks are either normal polarity or reversed polarity when they cool. This pattern can be used to estimate the age of parts of the earths crust)

Front 4

What does the movement of continents mean? (in terms of Britain)

Back 4

it means that different rocks in Britain formed in different climates

Front 5

What 4 processes in England have led to the formation of valuable resources (of coal, limestone, salt)

Back 5

1. mountain building

2. erosion

3. sedimentation

4. dissolving and evaporation

Front 6

What type of rock is limestone and what is it formed from?

Back 6

it is a sedimentary rock formed from seashells

Front 7

What colour is limestone and what does it mostly consist of ?

Back 7

it is grey/white and mostly consists of calcium carbonate

Front 8

How are sedimentary rock formed ?

Back 8

They are formed from layers of sediment laid down in lakes or sea

Front 9

Where does the sediment that makes sedimentary rocks come from ?

Back 9

it comes from shells and bones of sea creatures or from the erosion of pre-existing rocks

Front 10

What is erosion ?

Back 10

erosion is the natural weathering of large pieces of rock by rain and wind

Front 11

what does erosion create and what happens to what is created ?

Back 11

it creates tiny particles of sediment that are washed away and end up at the bottom of the sea or lake.

Front 12

What happens to layers of sediment over millions of years ?

Back 12

it gets buried under more layers of sediment and the weight pressing down squeezes out the water

Front 13

how are sediment particles held together to form rock ?

Back 13

fluids flowing through pores in the sediment deposit natural mineral cement

Front 14

How is coal formed ?

Back 14

it is formed over millions of years by the fossilisation of layers of plant matter

Front 15

what colour is coal and what does it mainly consist of ?

Back 15

it is black and mainly consists of carbon

Front 16

how is hard coal formed ? (mountain building)

Back 16

when coal deposits are put under high pressures and temperatures. (this can happen during the process of mountain building)

Front 17

What happens during evaporation to form sedimentary rocks?

Back 17

salt is left behind by evaporation

Front 18

how is salt obtained in Britain ?

Back 18

it is extracted from underground deposits

Front 19

why do geologists study sedimentary rocks ?

Back 19

to find evidence go the conditions under which they where formed

Front 20

Why do geologists look at fossils ?

Back 20

they tell you about the age of the rock, as well as the conditions when it was formed

Front 21

What does sedimentary rock formed under water contain ?

Back 21

it contains shells and ripples on it created by the sea or rivers

Front 22

what can you tell by the shape and grains found in sedimentary rocks ?

Back 22

you can tell if it was formed under water (water-bourne grains) or on the surface (air- blown grains)

Front 23

Where do chemical industries grow up ?

Back 23

where resources are available locally e.g. salt, limestone and coal in north west England

Front 24

Why is salt important ? (3)

Back 24

1. for the food industry

2. as a source of chemicals

3. to treat the roads in winter

Front 25

chemical name for salt?

Back 25

Sodium Carbonate

Front 26

name 2 places where salt can be obtained ?

Back 26

1. from the sea

2. from underground salt deposits

Front 27

How is underground salt obtained by mining ?

Back 27

1. Rock salt is drilled, blasted and dug out and brought to the surface using machinery

Front 28

What is underground rock salt used for ?

Back 28

1. it is used on roads to stop ice from forming

1. the salt can be separated and is used on foods or for making chemicals

Front 29

How does solution mining work ?

Back 29

1. water is injected into the salt deposit through the outer pipe

2. the water dissolves the salt to make a saltwater solution (brine)

3. pressure forces the brine up to the surface through the inner pipe

4. brine is then stored in wells above the surface and pumped to a refining plant.

5. impurities are removed from the brine in the refining plant and it is then pumped into containers.

6. The brine is then boiled to make the water evaporate living just the salt

Front 30

what is most of the salt made in solution mining use for ?

Back 30

1. table salt

2. chemical production

Front 31

why does the method used to obtain salt depend on how the salt is being used ?

Back 31

because some methods produce purer salts than others e.g. salt mining does not produce as purer salt than solution mining so the salt is used on roads and not for human consumption.

Front 32

How do methods of obtaining salt (mining) effect the environment ?

Back 32

1. land above mines can collapse into the holes- this is called subsidence

2. a lot of energy is need for mining, which usually comes from burning fossil fuels - this uses up finite resources and produces pollution

Front 33

Advantages of adding slat to food ?

Back 33

1. flavouring

2. preservative

Front 34

What are the health implications of eating too much salt ?

Back 34

1. high blood pressure - this leads to strokes and heart attacks

2. can increase the chance of getting stomach cancer

Front 35

What do the government departments (Department of Health, Department for environment, food and rural affairs) have a role in ?

Back 35

1. carrying out risk assessments in relation to chemicals in food to make sure they are safe

2. advising the public to how food affects their health

Front 36

What where alkalis needed for before industrialisation ? (4)

Back 36

1. to neutralise acid soils

2. make chemicals that bind natural dyes to cloth

3. convert fats and oils to soap

4. to manufacture glass

Front 37

What are traditional sources of alkali ? (2)

Back 37

1. Burnt wood

2. Stale urine

Front 38

What do alkalis do ?

Back 38

They neutralise acids to make salts

Front 39

what are 2 alkalis ?

Back 39

1. soluble hydroxide

2. carbonates

Front 40

what did, increased industrialisation in the 19th century lead to ?

Back 40

it led to a shortage of alkalis

Front 41

how did the process for manufacturing alkali from salt and limestone using coal as a fuel cause pollution ?

Back 41

it released large volumes of an acid gas (hydrogen chloride) and creating heaps of waste that slowly released a toxic and foul smelling gas (hydrogen sulfide)

Front 42

How can pollution problems sometimes be solved?

Back 42

by turning wastes into useful chemicals

Front 43

when oxidized what does hydrogen chloride convert to ?

Back 43

chlorine

Front 44

When hydrogen chlorine is oxidized to give chlorine, what are the properties of the compound like ?

Back 44

the properties the compound are completely different from the elements from which it is made

Front 45

What is chlorine used for ?

Back 45

1. to kill microorganisms in domestic water supplies

2. as bleach

Front 46

what was introduced to drinking water that made a major contribution to public health ?

Back 46

chlorination of water

Front 47

what is the disadvantage of chlorinating drinking water ?

Back 47

possible health problems from traces of chemicals formed by the reaction of chlorine with organic materials in the water

Front 48

what can be used to bring about a chemical change and make new chemicals ?

Back 48

an electric current, through the process called electrolysis

Front 49

How is chlorine obtained?

Back 49

by the electrolysis of salt solution (brine)

Front 50

important uses by industry of the sodium hydroxide produced by electrolysis of brine ?

Back 50

1. soap

2. ceramics

3. organic chemicals

4. paper pulp

5. oven cleaner

6. household bleach

Front 51

important uses by industry of the chlorine produced by electrolysis of brine ?

Back 51

1. disinfectants

2. killing bacteria (swimming pools and in domestic water supplies)

3. household bleach

4. plastics (e.g. PVC)

5. hydrochloric acid

6. insecticides

Front 52

important uses by industry of the hydrogen produced by electrolysis of brine ?

Back 52

1. used to make ammonia

2. used to change oils into fats for making margarine

3. used as a fuel in fuel cells, and for welding and metal cutting

Front 53

environmental impacts of large scale electrolysis ?

Back 53

1. requires a lot of energy, which comes from burning fossil fuels, then releasing co2 and using up finite resources

2. mercury is toxic and can get into rivers, and kill fish, and make people ill

3. Asbestos is used and it it is toxic and can cause lung cancer

Front 54

What is the problem with the a large number of industrial chemicals with widespread uses including consumer products?

Back 54

There is inadequate data to judge whether they are likely to present a risk to the environment and/ or human health

Front 55

Why do some toxic chemicals cause problem?

Back 55

1. they persist in the environment

2. they can be carried over large distances

3. can accumulate in food and human tissues

Front 56

What is PVC ?

Back 56

it is a polymer that contains chlorine as well as carbon and hydrogen

Front 57

What is the problem with the plasticizes used to modify the properties of PVC ?

Back 57

They can leach out from the plastic into the surroundings where they may have harmful effects

Front 58

What does a Life Cycle assessment involve (consider)

Back 58

the use of resources including

-water

-the energy input or output

- the environmental impact

of all these stages

Front 59

Life Cycle assessment stages

Back 59

1. making the material from natural raw materials

2. making the product from the materiel

3. using the product

4. disposing of the product