CHAPTER 14 Flashcards
What are the two ways of classifying natural resources
renewable or finite
what are finite resources
ones that are being used up faster than they can be produced
examples of finite resources 4
crude oil
limestone
metal ores
fossil fuels
what are renewable resources
one that are being produced at the same rate they are being used up
example of renewable resources
crops used to make biofuel
advantages of mining metal ores 3
useful products can be made
provides job for people
brings money into area
main disadvantages of mining metal ores 4
uses lots of energy
scars landscape
destroys habitats
lots waste
how are crops used in polymerisation
ethne can be made from ethanol which can be made from fermenting sugar can or sugar beet
what are natural resources
ones that form without human input from earth sea land and air
why are renewable resources now being used
sustainability - we must preserve the earth for future generations
what is limestone used for
to make cement and concrete
what is the aim of the reuse reduce recycle campaign
to reduce our waste energy usage and use of limited resources
why are ceramics fit for purpose 3
insulators of heat
brittle
stiff
why are polymers fit for purpose 3
insulators
flexible
easily molded
why are metals fit for purpose 3
malleable
good conductor
ductile
what is potable water
water that is safe to drink
what are the 3 characteristics of safe water
low levels of dissolved salts pH between 6.5 and 8.5 no bacteria
examples of uses of water 4
drinking
solvent
coolant
washing
process of collecting water form rain
rainwater falls to ground collects as surface water in reservoirs or percolate through the ground in aquifers
why does rainwater need to be cleaned before dinking
it dissolves some gases in the air as it falls
when in contact with land it will dissolve soluble materials too
what are the two ways in which is treated and why
filtration - to remove large solids
sterilisation - kill harmful microbes
how I water sterilised
addition of chlorine or using ultraviolet light or ozone
when do cpuntries need to drink salt water
when there isn’t enough rain
how to make salt water safe to drink
distillation
how to distill water
heat
the water will boil and form steam
leaving salt crystals below
the steam will condense into water in the condensing column
how is reverse osmosis used to distil salty water
the water is passed through a membrane which only allows water molecules to pass through
process of cleaning water
passes through mesh to catch large objects as it enters water treatment works
enters settlement tank - sand and soil settle out
aluminium sulfate and lime added to water
passes through fine mesh to remove any remaining particles of mud of salt
clorine is added to sterilise pH of water
checked to ensure it is neutral
stored in tanks and distributed to consumers
process of treating sewage water
screening passes through mesh to remove large solids
moved into settlement tank solid sediment is allowed to settle whilst liquid sits on the top and flows into the next tank
air is pumped into the tank to encourage bacteria to break down any harmful, organic matter in it
the useful bacteria settle as sediment where it is removed and recycled
what is the effulent in water treatment
the water liquid above the sludge
sources of waste water 3
the haber process
agricultural systems
homes
what happens to the sludge produced when treating sewage
microorganisms anaerobically digest
the organic matter methane gas and biogas are produced
what is the methane produced form anaerobic digestion used for
energy source
what is sludge from sewage treatment used for
fertilisers
what is the biogas produced form anaerobic digestion used for
energy source
what is a life cycle assessment
it looks at every stage of a products life and assesses its impact on the environment
where does copper come from
copper ores
what are the two main methods of extracting copper from the core
sulfuric acid is mixed with the ore to create copper sulfate before the copper metal is extracted
smelting - copper ore is heated to a high temperature with air to produce impure copper
what are the four stages of a products life that has an effect on the environment that a life cycle assessment looks at
getting raw materials
manufacture and packaging
using the product disposal
how is a life cycle assessment carried out 2`
looks at all the main energy and material inputs
the environmental impact of inputs and outputs
examples of outputs of a life cycle assessment that impact the environment 3
emissions
energy dissipation
waste
how can sourcing raw materials for a product impact the environment 2
extraction leades to pollution
raw materials need to be processed which uses a lot of energy
how can manufacturing and packaging a product have an impact on the environment
uses a lot of energy
waste chemicals from manufacturing
pollute environment
How can using a produce impact the environment 2
the purpose of the product can impact the environment for example fossil fuels being burnt or fertiliser leavhing chemicals into streams the longer a product is used for the more energy needed
how can the way in which a product is disposed impact the enivornment 3
often left in landfill sites - pollutes land and water
products might be incinerated
energy is used to transport waste to landfill= energy
probems with LCAs 2
selective LCAs which can only shows some information
may be biased to make a company look better producing an lsa is subjective as it is the persons own opinions about how important an issue is
the impact an issue has that are published
don’t take into account cost or performance
what is sustainable development
an approach to development that ensures the needs of present society are met whilst preserving earth for futue generations
what are the aims of the reduce reuse recycle campaign 3
to reduce our use of limited resources
to reduce the waste we produce
to reduce our use of energy
why is it important to recycle metals
mining and extracting metals takes a lot of energy -produced by fossil fuels recycling uses much less energy and is therefore cheaper
how aluminium sourced
extracting from aluminium oxide at high temperature by electrolysis
how are metals recycled
they are melted down and cast in the shape of the new product
why is extracting iron so bad
most of the energy needed comes form burning fossil fuels
what is a blast furnace used for
extracts iron form its ore at a high temperature using carbon
why is the recycling of copper often more difficuly
it is often alloyed with other metals
how can recycling glass help sustainability
reduces the amunt of energy needed to make new glass
reduces the waste created when glass is thrown away
why are glass bottles easy to recycle
they can often resued with reshaping
process of recycling glass
separated by colour and chemical composition
glass is crushed and melted
it is then reshaped for use in new glass products
3 benefits of recycling metals
conserves limited supply of metalores
reduce energy/pollution
problems with mining 3
huge pits are left behind that scar the landscape
destroy habitats
grounwater can become acidic
what greenhouse gas is released in the extraction of iron
co2
one way in which chemists have helped sustainability
catalyst reduce the amount of energy required for industrial processes
what is thermal decomposition
when the bonds in reactants break because they are exposed to high temperatures
describe the main process used to maintain pur copper
copper ore is mined
copper ore is smelted
impure copper is used as positive electrode In electrolysis
3 main problems of smelting copper
uses huge amounts of energy and electricity - expensive pollution of environment
why is electrolysis used to produce pure copper from impure copper
impure copper used as positive electrode
metal ions are always positively charge
therefore they are attracted to and deposited at the negative electrode
half equation for the electrolysis of copper at the positive electrode
cu s -> cu2 aq+ +2e-
what happens at the negative electrode in the electrolysis of copper
oxidation
what happens at the positive electrode in the electrolysis of copper
reduction
half equation for the electrolysis of copper at the negative electrode
cu2 aq + 2e- ->cu s
how can iron be used to extract copper from copper sulfate solution
iron displaces copper from its solutions
equation for iron + copper sulfate
iron + copper ii
sulfate -. iron ii
sulfate + copper
what are the two new ways of extracting copper from low grade ores
bioleaching
phytomining
process of phytomining
plants are grown in soil that contains copper
it builds up in leaves as plants cant use it
plants are burned
copper extracted from copper compudns in ash the copper ions can be leached by adding sulfuric acid this makes a solution of copper sulfate
displacement by iron and then electrolysis = pure copper
process of bioleaching
bacteria feed on low grade metl ores
they convert copper compounds in the ore into soluble copper compounds
the solution of copper ions produced can be used in a displacement reaction with iron
then electrolysis to produce pure copper
why is only 20% of copper currently created by bioleaching
it is very slow
