Using Resources Flashcards
what are ceramics?
- non-metal solids
- with high mpts
- not made from carbon based compounds
- insulators
- brittle
- stiff
what are ceramics made from clay?
give examples of its uses
- soft
- from ground
- mouldable
- fired at high temps to harden
- pottery/bricks
what are ceramics made from glass?
- transparent
- moulded when hot
- brittle when thin
how to make soda-lime glass?
how to make borosilicate glass?
- heat mixture of limestone, sand, sodium carbonate til melts cools to glass
- higher mpt and uses sand and boron trioxide
what are composites?
what do their properties depend on?
- materials embedded in another
- properties of materials used
explain fiberglass
- fibres of glass embedded in plastic polymer matrix
- low density like plastic
- very strong like glass
- used in skis/boats/surfboards
explain carbon fibre composites
give examples of its uses
- plastic polymer matrix
- reinforcement either carbon nanotubes
- or carbon fibres: long carbon chains bonded together
- very strong and light
- aerospace/sportscar manufacturing
explain concrete composites
- aggregate (sand and gravel) embedded in cement
- very strong
explain natural wood composite
- cellulose fibres
- held together by organic polymer matrix
what influences properties of polymers?
- how its made
- what its made from
what does the properties of poly(ethene) depend on?
- catalyst
- reaction conditions
low density poly(ethene) is made from ethene at…
- moderate temp
- high pressure
- catalyst
- flexible
used for bags and bottles
high density poly(ethene) is made from ethene at…
- lower temp
- lower pressure
- different catalyst
- more rigid
- used for tanks/drainpipes
the monomers that a polymer is made from determines…
type of bonds that form between polymer chains
thermosoftening polymers contain…
- individual polymer chains entwined
- weak forces b/t chains
- melt plastic and remould
thermosetting polymers contains…
- monomers which cross-link b/t polymer chains
- hold in solid structure
- don’t soften when heated
- strong
- hard
- rigid
what are properties of polymers?
- insulators
- flexible
- easily moulded
what are properties of metal?
- malleable
- good conductor
- ductile
- stiff
- shiny
make bronze alloy?
properties?
uses?
- copper + tin
- harder than copper
- statues
make brass alloy?
properties?
uses?
- copper + zinc
- more malleable than bronze
- lower friction required in taps
make gold alloy?
carats?
uses?
- pure gold soft so hardened with Zn, Cu, Ag
- 18 carats= 18/24 pure gold
- jewellery
make aluminium alloy?
properties?
uses?
- too soft so hardened with small amounts of other metals
- low density
- aircraft manufacture
what are natural resources?
- form without human input
- from earth, sea, air
alternative process of natural resources?
- replaced by synthetic product or improved by man-made processes
- rubber extracted from tree sap but manmade polymers used in tyres
what is a renewable source?
-used up at same rate it is being replaced
what is a non-renewable resource?
-used up faster than its being replaced
give examples of non-renewable materials?
- fossil fuel
- nuclear fuel (uranium, plutonium)
- minerals
- metals found in ores
what is sustainable development?
- meets needs of present society
- without damaging ability to meet same need in future generations
what are examples of unsustainable processes?
what can u do to reduce it?
- extraction: lots energy used and waste produced
- processing resources into useful materials: energy from finite resources
- use less
how do chemists help sustainable developments?
give example
- adapt to use less finite resources
- reduce damage to environment
- e.g catalysts reduce energy needed
extracting from low-grade ores using bioleaching?
- convert Cu compounds into soluble ones to seperate from ore
- leachate has Cu2+ extracted by electrolysis
- or displaced with more reactive iron
extracting from low-grade ores using phytomining?
- grow plants in Cu soil
- builds in leaves
- harvested, dried, burned in furnace
- ash has soluble Cu compounds extracted by electrolysis
- or displacement with more reactive iron
advantage to bioleaching and phytomining compared to traditional methods?
disadvantage?
- smaller impact to environment
- slow
why is mining and extracting metals bad?
why is recycling better?
- lots of energy from fossil fuels
- less energy needed
- conserves finite material
- less waste sent to landfill
how are metals recycled?
- melting then casting into shape
how is recycling glass sustainable?
- less energy needed to make glass
- less waste created when used glass thrown away
how is glass recycled?
- bottles reused
- seperated by colour/chemical composition
- crushed, melted, reshaped
- e.g bottles, jars, insulating glass wool
