C10 Flashcards
What do humans ues the earth resources?
warmth, shelter, food
and transport.
Natural resources are supplemented by algriculture to provide….
food,
timber, clothing and fuels.
WHta are the finite resoucrs form the earth processed to provide?
energy and materials
What is the importance of Chemistry in life?
- improving agricultural and
industrial processes to provide new products - sustainable
development
Define sustanible development
development that meets the needs of current
generations without compromising the ability of future generations
State examples of natural products that are supplemented or
replaced by agricultural and synthetic products
-Natural firtiliser ( maure)
-Rubber
What does dinking water nedd sufficently low levels of ?
dissolved salts
and microbes( bacteria)
Water that is safe to drink is called…
potable water
Is potable water chemically pure? Explain
Potable water is not pure water in the chemical sense because it
contains dissolved substances.
What do methods to produce poatble water depend on?
available
supplies of water and local conditions ( access to sea ect)
Whta type of water is rainwater?
Fresh water
How is poatble water prodced in the UK?
- choosing an appropriate source of fresh water
- passing the water through filter beds
- sterilising.
What are the sterlising agents used for poatable water?
chlorine, ozone or
ultraviolet light.
Define fresh water
water with low levels of
dissolved substances
Rain water collects in what 3 places
ground and in
lakes and rivers
If supplys of freshwater are low…
desalination of salty water or
sea water may be required
What re the 2 methods of desalination ? How much energy do theses processes require?
1.distillation
2. processes that use membranes such as reverse osmosis-> put saltwater through partially permiable membrane and the salt dosn’t pass through
=>processes require large amounts of energy
Analysis and purification o f water samples from different sources. To include pH measurement,
removal of dissolved solids and distillation.
- Use universal indicator to test the pH of the water.
- Measure and record the mass of an empty evaporating basin.
- Pour 10 cm3
water into the evaporating basin and evaporate the water using a
bunsen burner until the most of the water has evaporated. - Once the evaporating basin is cool, reweigh and record the change in mass.
- Calculate the mass of dissolved solids in the water.
RQ: Anlysisng and purifying water samples
How would you tell the pH of a water sample
Add Universal indicator
What 2 prosess produce larged amounts of waste water
Urban lifestyles and industrial processes
Sewage and agricultural waste water require removal
of…….
organic matter and harmful microbes
Industrial waste water may
require removal of…..
organic matter and harmful chemicals
Are the Earth metal ores limited?
YES
What ore is becomeing scarce?
Copper
Describe sewage treatment
- screening and grit removal
- sedimentation to produce sewage sludge and effluent
- anaerobic digestion of sewage sludge
- aerobic biological treatment of effluent.
Whta are new ways of extracting low grade ores?
phytomining, and bioleaching
What does phytomining, and bioleaching avoid compaired to traditional methods?
digging, moving
and disposing of large amounts of rock
What is Phytomining?
-Uses plants to absorb metal compounds
-The plants are harvested and then burned to produce ash that contains metal
compounds.
What is bioleaching?
Uses bacteria to produce leachate solutions that
contain metal compounds.
Copper can be obtained from solutions of copper
compounds by…
displacement using scrap iron or by electrolysis
WHta is an LCA
Life cycle assessments (LCAs) are carried out to assess the
environmental impact of products
How does LCA asses the envirmental impact of a product?
- extracting and processing raw materials
- manufacturing and packaging
- use and operation during its lifetime
- disposal at the end of its useful life, including transport and
distribution at each stage.
Why is an LCA is not a purely objective process. What can this cause?
-Allocating numerical values to
pollutant effects is less straightforward and requires value judgements
-Use of water, resources, energy sources and production of some wastes can be fairly easily quantified.
=>Selective or abbreviated LCAs can be devised to evaluate a product
but these can be misused to reach pre-determined conclusions, eg
in support of claims for advertising purposes.
Carry out an LCA for a plastic bag.
Raw material: Crude oil
Manufacturing and Packaging: Crude oil-> fracktional ditilation-> cracking-> plymerisation => waste is reduced other uses for the other fractions of crude oil
Using the product: reused can be used for other things
Disposla:Reyclable not biodegradable (landfill=pollute)
Carry out an LCA for Paper bag.
Raw material: Timber
Manufacturing and Packaging: Pulped timer processed with lots energy. Lots of waste made.
Using product: only once
Product disposal:Biodegradable and non-toxic, can be recycled
Ways of reducing the use of resources
The reduction in use, reuse and recycling of materials by end users
reduces the use of limited resources, use of energy sources, waste
and environmental impacts.