Using resources

Question 1

what do humans rely on and where does it come from?

Answer 1

relay on earth resource to provide them with food,shelter ,warmth and transport
all resources come from the earth crust,ocean and atmosphere which are renewable (timber ) or finite (metal ores)

Question 2

How do humans care for the earth/What is agriculture?

Answer 2

they take care of it so the earth does become to polluted
as population increases human relay on agriculture
(the art and science of cultivating the soil, growing crops and raising livestock)to supplement or even replace such resources

Question 3

What does water contain?

Answer 3

naturally contains microorganism and dissolved salts but in order for us to drink this we need them to be at low levels for it to be safe enough for us to drink

Question 4

What is potable water?

Answer 4

water that is good quality and safe to drink

Question 5

How is potable water produced?

Answer 5

1) fresh water from a suitable source (river,lake away from polluted areas is collected
2) it is passed through a filter bed to remove solid particles

Question 6

What elements in group 7 is added to making potable water?

Answer 6

3) chlorine gas is added to kill harmful microorganism

4) fluoride is added to drinking water to reduce tooth decay

Question 7

How can water be sterilized and how can the taste of water be improved?

Answer 7

Ozone and ultraviolet can also be used to sterilize water
to improve quality of water more dissolved substances can be removed by passing the water through a filter containing carbon ,silver and ion exchange resins

Question 8

What is desalination?

Answer 8

can be done if fresh water supplies are limited to produce pure water
can be done by distillation or osmosis
both process are very expensive and use a lot of energy

Question 9

What happens during distillation?

Answer 9

The water is boiled to produce steam

the steam is condensed to produce pure liquid water

Question 10

How is large amounts of water wasted?

Answer 10

wasted by homes,agricultural process and industrial process

the waste must be treated before it can be released back in to the environment

Question 11

What needs to be removed from sewage and agricultural and industrial waste water?

Answer 11

organic matter
harmful organisms
toxic chemicals

Question 12

What does a sewage treatment include?

Answer 12

screening and grit removal
sedimentation to produce sewage sludge and effluent
anaerobic digestion of sewage sludge
aerobic biological treatment of effluent

Question 13

Why is copper a useful metal?

Answer 13

it is a good conductor of electricity and heat
easily bent,yet hard enough to make waterpipes and tanks
does not react with water so long lasting

Question 14

What is smelting?

Answer 14

when copper is extracted from copper-rich ores by heating the ores with a carbon furnace and then be purified by electrolysis

Question 15

How can copper be obtained?

Answer 15

from solution of copper salt by electrolysis (positive copper ions move towards the negative electrode and form pure copper)
displacement using scrap irons

Question 16

How can copper be extracted?

Answer 16

low grade ores

contaminated land by biological methods

Question 17

What is phytomining and the process?

Answer 17

uses plant to absorb copper
as the plant grows they absorb and store copper
the plant is then burnt and the ash produced contains copper in relatively high quantities

Question 18

What is bioleaching and the process?

Answer 18

uses bacteria to extract metals from low grade ores
a solution containing bacteria is mixed it a low grade ore
the bacteria converts the copper into a solution known as a leachate solution from which copper can easily be extracted

Question 19

What is rusting?

Answer 19

metals corrode when they react with oxygen and water in the environment
the term rusting is when an iron object or object containing iron corrode

Question 20

How can we prevent corrosion?

Answer 20

painting
electroplating
greasing a metal object to stop oxygen and water from reaching the surface and therefore stop corrosion from occurring

Question 21

What is sacrificial protection?

Answer 21

more reactive metal is placed in contact with the metal
EG-blocks of the more reactive magnesium metal are attached to the iron or steel object
as magnesium is more reactive than iron it reacts and loses electrons instead of the iron

Question 22

What is galvanising and the process?

Answer 22

used too protect iron or steel projects
the object is coated in a layer of zinc
the zinc layer stops oxygen and water from reaching the metal and stops the corrosion
if the surface of the zinc is scratched it does not matter the zinc provides sacrificial protection

Question 23

How is aluminium protected from corrosion?

Answer 23

by a thin layer of aluminium oxide which acts as a barrier and prevents the aluminum from reacting further

Question 24

What is glass?

Answer 24

non-crystalline solid

Question 25

How is soda lime glass made?

Answer 25

made by heating a mixture of sand ,sodium carbonate and limestone and is used as window glass

Question 26

How is borosilicate glass made?

Answer 26

made by heating sand and boron trioxide to a high temp than that used for producing soda-lime glass
used to make chemical glassware,cooking equipment and car headlights

Question 27

How are pottery and bricks made?

Answer 27

clay ceramics
made by shaping wet clay and then heating them in a furnace
in the furnace water is removed and chemicals reaction take place that make the object retain is shape and become harder and stronger

Question 28

What is a composite material?

Answer 28

consists of 2 materials with diff properties
the material are combined together to produce a material that has its own improved properties
EG concrete and fiberglass

Question 29

What is the life cycle assessment?

Answer 29

used to assess the environmental impact a product has over its lifetime
provide a way of comparing several alternative products to see which one causes the least damage to the environment

Question 30

What do scientist measure the impact of?

Answer 30

extracting raw materials
processing raw materials
manufacturing the product
how the products is used 
how the product transported and disposed of at the end of its life

Question 31

Why should we reuse and recycle as much as possible?

Answer 31

to save money and energy
make sure natural resources are not used up unnecessarily
reduce the amount of waste produced

Question 32

How can glass,plastics and metals be recycled?

Answer 32

waste glass can be crushed,melted and reused
some waste plastics can be recycled to make fleece material
metals can be recycled by melting them down and then making them into new objects

Question 33

What is the haber process?

Answer 33

used to manufacture ammonia which is used to produce nitrogen based fertilisers

Question 34

What are the raw materials in the Haber process?

Answer 34

purified nitrogen-from the fractional distillation of liquid air
hydrogen-from natural gas or steam

Question 35

What conditions is the nitrogen and hydrogen put under?

Answer 35

the nitrogen and hydrogen are passed over a iron catalyst at a modern temp (450) and at high pressures (200)

Question 36

Describe the haber process

Answer 36

some hydrogen and nitrogen forms to make ammonia
because reaction is reversible some of the ammonia produced will break down again into nitrogen and hydrogen
on cooling the ammonia liquefies an can be removed from the mixture ]the unreacted nitrogen and hydrogen are recycled

Question 37

Choosing conditions P1

Answer 37

the reaction between hydrogen and nitrogen is exothermic
high reaction temp faster rate or reaction but low yield of ammonia
low reaction temp ,high yield of ammonia,very slow reaction

Question 38

Choosing condition P2

Answer 38

high pressure,high yield

iron catalyst increase ror

Question 39

Why do w use fertilisers?

Answer 39

to replace the essential element in soil that are used by plants as they grow
plants absorb these chemicals in their roots so fertilizers must be soluble in water
to grow well plants need nitrogen phosphorus and potassium

Question 40

What are NPK fertilisers?

Answer 40

contain compounds of all 3 elements

formulations of various salts that are mixed together to give appropriate percentage of each element

Question 41

How many numbers does NPK fertilizers consist of?

Answer 41

3 numbers
1st % of nitrogen
2nd amount of phosphorus
3rd amount of potassium

Question 42

Why is Ammonia used

Answer 42

alkaline gas that dissolves in water 
increase nitrogen content of soil
can be oxidised to produce nitric acid
neutralise nitric acid to produce ammonium nitrate 
fertilizer rich in nitrogen

Question 43

Why are nitrogen based fertilizers important?

Answer 43

important chemicals because they increase the yield crops

Potassium chloride and potassium sulfate are soluble and can be used directly as fertilizers

Question 44

Why is phosphate rock used?

Answer 44

high levels of phosphorus compounds

however they are insoluble so they cannot be used directly as fertilizers

Question 45

How can phosphate rock be processed to make new useful products?
(nitric acid)

Answer 45

treated with nitric acid
to produce phosphoric acid and calcium nitrate
phosphoric acid is then neutralized with ammonia to produce ammonium phosphate

Question 46

How can phosphate rock be processed to make new useful products?
(sulfuric acid)

Answer 46

treated with sulfuric acid to make single superphosphate-mixture of calcium phosphate and calcium sulfate
-can be reacted with phosphoric acid to make triple superphosphate