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.
Examples of materials made form limited raw resources
Metals, glass, building materials, clay ceramics and most plastics
Obtaining ____ materials
from the Earth by _______ and ______ causes ___ ____ .
raw
quarrying
mining
environmental
impacts
Define Corrosion
destruction of materials by chemical reactions with
substances in the environment
What is an example of Corrosion?
Rusting
What is needed for rusting to occur?
Both air and water are necessary (for iron) to rust.
How can Corrosion be prevented?
1.Applying a coating-> acts as a
barrier, such as greasing, painting or electroplating. Aluminium has
an oxide coating that protects the metal from further corrosion.
2. Sacrificial protection->Some coatings are reactive and contain a more reactive metal to provide sacrificial protection, eg zinc is used to galvanise iron
What kind of melts are most use in everyday life?
Alloys
What is Bronze an Alloy of ?
copper and tin
What is Brass an Alloy of?
copper and
zinc
s=z
Whta is Gold an Alloy with?
silver, copper and
zinc
How is the proportion of gold in Alloys measured in?
Carats
24=100% gold 18=75%
What is steeel an Alloy of?
iron that contain specific amounts of carbon and
other metals.
What are the properties of high carbon steel?
strong but brittle
What are the properties of low carbon steel?
softer and more easily shaped
What is Stanless steel an alloys of?
chromium
and nickel
What are the the properties of Stainless steel?
hard and resistant to corrosion.
What are the properties of Aluminum Alloys?
low density
High carbon steel uses
Construction
low carbon steel uses
Making car body panles
Stainless steel use
Cutlery
Bronze uses
Statue, coins ect
Uses of brass
instriment
What type of glass is most of the glass we use ?
soda-lime glass
How is soda-lime glass made?
heating a
mixture of sand, sodium carbonate and limestone
How is Borosilicate
glass made?
made from sand and boron trioxide
Wich melts at a higher temprature soda-lime or Borosilicate
glass
Borosilicate
glass
How are clay ceramics made?
shaping
wet clay and then heating in a furnace.
What is the ues of Clay ceramics?
pottery and bricks
Whta doe the properties of polymers depend on?
1.What monomers they are
made from
2.Conditions under which they are made
Whta is both low density (LD) and high density (HD) poly(ethene) produced form?
ethene
What happens to Thermosoftening polymers when heated?
melt
What happens to Thermosetting polymers when heated?
Do not melt
What is Harber process used to manufacture?
ammonia
What are the uses of Ammonia
produce nitrogen-based fertilisers
Whatare the 2 reactants used in the Habour process? WHere are they supplyed from?
nitrogen-> air
hydrogen-> natural gass
What temprature and presure is the Haber process dones at?
High temperature->about 450°C
High pressure->about 200
atmospheres
Whta type of catalyst is used in the Habour process
catalyst of iron
Whta type of reaction is the Haber process? Explian what this means.
reaction is reversible so some of the ammonia produced breaks down into nitrogen and hydrogen
What is the word equation for the Harbour process?
Descibe the Habour process
N2+3H2 ⇌ 2NH3
What happens to the position of the equalibrum whe the presure is increased?
Moves to the side with less moles N2+3H2 ⇌ 2NH3
More product produces
What is the temp trade off?
N2+3H2 ⇌ 2NH3
-Foward reaction = exothermic
Increasing tmeprature increases rate of raction wich shift equalibrum to the left decresing yeild
-trade off between rate of raction and yeild
-exceee enrgy can heat up other parts of rection or make electricity
What is the trade off interms of presure?
N2+3H2 ⇌ 2NH3
Increasing prsure increses yeril but high presure is very expensive
How can recycleing Hdrogena nd nitrogen reduce cost
less new raw material needed= less cost
Describe te Habour process
The purified gases are passed over a catalyst of iron at a high
temperature (about 450°C) and a high pressure (about 200
atmospheres). Some of the hydrogen and nitrogen reacts to form
ammonia. The reaction is reversible so some of the ammonia
produced breaks down into nitrogen and hydrogen
=>On cooling, the ammonia liquefies and is removed. The remaining
hydrogen and nitrogen are recycled.
WHta caon amiona be used tot manufacture?
ammonium salts and nitric
acid
What is NPK fertiliser mad of?
Compounds of nitrogen, phosphorus and potassium are used as
fertilisers
What are the uses of ferilisers
improve agricultural productivity
How are the compunds needed in NPK fertilisers obtained?
Obtained by mining:
->Potassium chloride ( can disovle in water)
->potassium sulfate (can dissolve in water)
->phosphate rock ( cann’t be used dircetly a
How are Phosphate rock is treated so they can be used as fertilisers?
treated with nitric acid or sulfuric acid
How do we make amonium sulfate in lab?
1.25 cm3 of ammonia solution is measured using a measuring cylinder or volumetric pipette and poured into a conical flask.
2.Two drops of methyl orange indicator are added. This will turn yellow in the alkaline ammonia solution.
3.Dilute sulfuric acid is added from a burette slowly until the methyl orange indicator turns orange. If too much acid is added it will turn red.
4.The volume of sulfuric acid which has been added is recorded, and then the neutral solution of ammonium sulfate which contains the indicator is thrown away.
5.The experiment is repeated without the indicator but with the same volumes of ammonia and sulfuric acid.
6. The ammonium sulfate is crystallised by evaporating the water and drying the crystals in an oven or desiccator.
Where does the potassium used in NPK fertilisers come from?
from mining KCl and K2SO4
What salts are manufactured from ammonia and how?
-ammonium phosphate ((NH4)2PO4) (made by reacting ammonia with phosphoric acid)
-ammonium sulfate ((NH4)2SO4) (made by reacting ammonia with sulfuric acid)
-ammonium nitrate (NH4NO3) (made by converting ammonia into nitruc acid then reacting ammonia with the nitric acid)
What salts are manufactured from phosphate rock and how?
-single superphosphate (made by reacting phosphate rock with sulfuric acid)
-triple superphosphate (made by reacting phosphate rock with nitric acid to make phosphoric acid and then reacting the phosphoric acid with phosphate rock)
-ammonium phosphate (made by reacting phosphate rock with nitric acid to make phosphoric acid and then reacting the phosphoric acid with ammonia)
What salts are mined?
-potassium chloride (KCl)
-potassium sulfate (K2SO4)
