C10-Using Our Resources Flashcards
What is the adv and disadv of:
1) Bioleaching
Adv-(2)
Disadv- (2)
2) Phytomining
Adv-(2)
Disadv- (2)
1) Bioleaching ADV: -uses waste from quarrying -energy efficient DISADV: -v slow process. -a solution of toxic chemicals which run off into the rivers and it takes a long time to stop the process if river pollution occurs.
2) Phytomining
Adv:
-slow but can be made more efficient using quick growing plants.
-land contaminated with low-grade copper ore can be used for the plant to grow. (decontaminates ground)
Disadv:
- impure copper- uses electrolysis which is not energy efficient
- combustion of plants in phytomining BUT more concentrated copper is left.
Describe bioleaching specifically to bacteria.
-Bacteria break weak copper sulphate bonds which release copper metals and separate and forms Cu metals and forms stronger bonds. More energy efficient.
Define copper-rich ores.
Contains high levels of copper, economically viable to extract copper from ore to make good profit- finite source.
What do both methods of phytomining and bioleaching help with?
- Both methods help extract copper from low grade copper ores and prevent mining or quarrying therefore prevents noise, dust pollution or even destruction to habitats
Compare phytomining and bioleaching (4)
Phytomining
- much more slow process
- not energy effiicient as it would require electrolysis and impure copper would be produced.
- combustion of plants but produces more concentrated copper.
- decontaminates ground.
Bioleaching:
- produces a solution of toxic chemicals- more harmful to the environment as it can run off into seas.
- energy efficient and uses waste from quarrying.
- v slow process.
Define ceramics. What are the common 2 types?
- Non-metal solids with high melting points that aren’t made from carbon-based compounds. They can be electrical insulators and can be used to make plates, ornaments, pots and jugs.
- Some ceramics ca be made from clay which is a soft material when dug out of the ground; clay ceramics, including pottery and bricks, are made by shaping wet clay and then heating in a furnace.
- Another example of ceramics is glass which is generally transparent and can be moulded when hot and can be brittle when thin
Define the 2 types of glass? State some uses?
1) Soda lime glass:
- most of the glass we use, it is made by heating a mixture of sand, sodium carbonate and limestone until it melts and when the mixture cools, it comes out as glass.
2) Borosilicate glass:
- has a higher melting point than soda lime glass. It’s made in the same way as soda lime glass, using a mixture of sand & boron trioxide.
- used in ovenware and for tubes as it melts at higher temp
They look similar but they have different chemical compositions.
Define composites?
-Composites are usually made up of two or more material embedded in one another. Fibres or fragments of a material(known as reinforcement) are surrounded by a matrix acting a binder
List composite materials, what their made from, their material and their uses. (5)
1) Fibreglass- consists of fibres of glass embedded in a matrix made made of polymer(plastic)- low density but is v strong (like glass)- used for skis, boats, surfboards.
2) Carbon fibre composites also have a polymer matrix, the reinforcement is either made from long chains of carbon atoms bonded together(carbon fibres) or from carbon nanotubes- composites are b strong and light so aerospace or sports car manufacturing.
3) Concrete- made from aggregate(a mixture of sand and gravel embedded in cement- v strong- building material.
4) Wood- natural composite of cellulose fibres, held together by an organic polymer matric- tables, chairs, furnitures.
5) Reinforced concrete- steel rods in a concrete atrix-> strong, flexible-> bridges.
What are the two types of polymers? 3 points for each
1) Thermosetting:
- contain special monomers that have strong covalent bonds forming cross-links between the polymer chains, holding the chains together and in a solid structure.
- These polymer chains do not soften when heated- strong, hard and rigid. and the chains are fixed together by strong covalent bonds but will eventually char at high temps.
- covalent ‘cross-link’ do not allow the chains to separate.
2) Thermosoftening
- contain indivi polymer chains- no cross link as they have weak intermolecular foces between chains that are entertwined so when heated, the im forces break and polymer becomes soft.
- when cooled, the im forces bring the polymer molecules back together and the polymer hardens again; this type of polymer can be remoulded into new shapes->
- polyethene, polyester, nylon.
What are the two types of polyethene?
1) LD(low dens) is made from ethene at a moderate temp under a high pressure and a catalyst- it’s flexible and can be used for bags and bottles.
2) HD(high den) polyethene is amde from ethene but at a lower tem and pressure with a diff catalyst- more rigid so can be used for watertanks and drainpipe- cannot be used for hot water
What do the properties of the polymer depend on?
The properties of polymers depend on what monomers they are made from and the conditions under which they are made.
Compare the production stages and use of bottle made from soda lime glass and those made from HD poly(ethene)
HDPE- cracking of naptha, polymerisation- 3 stages of production.
Glass- 2 stages of production so fewer stages so may be made quickly.
Discuss the Haber process:
- where can these materials be extracted from?
- the conditions.
- equation.
- what happens at cooling?
- what’s specific about the conditions?
-The Haber process is used to manufacture ammonia, which can be used to produce nitrogen-based fertilisers.
The raw materials for the Haber process are nitrogen and hydrogen.
-Nitrogen:- which can be removed from air through distillation and hydrogen made from methane gas(natural gas)
-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:
nitrogen + hydrogen ammonia
N2 + 3H2 ->< 2NH3
-On cooling, the ammonia liquefies and is removed. The remaining hydrogen and nitrogen are recycled as they are finite sources and expensive to extract
-Conditions for haer process are selected ver carefully to ensure a balance between the ROR and the yield of ammonia made.
How does the condition of haber process affect ROR
and the effect on yield?
ROR:
1) Increasing temp- increases the ROR as the particles will have more energy so this will result in more freq succesffuly collisons.
2) high ressure- vol decreases so they collide more freq
4) catalyst- increases ror as it offers an alternative patheway with a lower activitation energy.
Yield:
1) high temp- pos of eq towards endo- reduce yield of ammonia- compromise is needed of 450 to shift towards exo and make more ammonia.
2) high pressure- towards side with fewer moles to decrese pressure- increase yield of ammonia.
3) catalyst- no effect on position of equillibra or yield as catalust increases rate of backward and forward reaction by the same amount.
