2907137
Descrição
FlashCards por RosettaStoneDecoded, atualizado more than 1 year ago
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Criado por RosettaStoneDecoded
mais de 9 anos atrás
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| Questão | Responda |
| what two types of atoms are involved in IONIC bonding? | metal and non-metal |
| in IONIC bonding, which atom loses electrons to becomes POSITIVELY charged? | the metal atom |
| what does OIL RIG stand for? | oxidation is loss, reduction is gain |
| what two atoms are involved in COLVALENT bonding? | both non-metal atoms |
| what is limestone made of? | calcium carbonate |
| what does LIMESTONE form when THERMALLY DECOMPOSED? | calcium oxide and carbon dioxide |
| when acid is added to CALCIUM CARBONATE, what is formed? | calcium salt, carbon dioxide and water |
| what is produced when you react CALCIUM OXIDE with WATER? | calcium hydroxide |
| what is the test for CARBON DIOXIDE? | bubbling it through limewater (calcium hydroxide) |
| why in the test for CARBON DIOXIDE does the limewater become cloudy? | because the carbon dioxide reacts with the calcium hydroxide to form calcium carbonate and water |
| how is cement made? | powdered limestone is heated in a kiln with powdered clay |
| how is mortar made? | cement is mixed with sand and water |
| how is concrete made? | cement is mixed with sand and aggregate (water and gravel) |
| what are the cons of quarrying limestone? | creates large ugly holes in the landscape noise and dust pollution destroys animals habitat limestone needs to be transported away waste produces ugly tips |
| what are the pros of quarrying limestone? | can be used to build houses/roads chemicals extracted are used in medicine can be used to neutralise acidic soil/water neutralises sulphur dioxide in chimneys creates jobs landscaping and restoration afterwards |
| what are the advantages of limestone products? | can be used as perfect building materials widely available/ cheap/ easy to cut concrete can be moulded fire-resistant/ doesn't rot doesn't corrode |
| what are the disadvantages of limestone products? | low tensile strength and can crack ugly will react with acid rain |
| what is an ore? | rock which contains enough of the metal to make it worth extracting |
| why might the economics of metal extraction change over time? | if prices drop it might not be worth extracting more of it as technology improves, we can extract metal which wasn't previously extractable and would therefore be worth it |
| what are the two different methods of extracting metal? | electrolysis reduction with carbon |
| how can you extract copper with reduction? | heat in a furnace with carbon - smelting |
| why is electrolysis often used instead for copper extraction? | copper produced from smelting is often impure and this causes problems when used for electrical wiring - when impure copper is a poor conductor |
| what is electrolysis? | breaking down of a substance using electricity |
| what is an electrolyte? | a liquid required for the breaking down of a substance through electrolysis as it conducts the electricity |
| what is an electrolyte usually made of? | metal salt solutions made from the ore, or molten metal oxides |
| how does the electrolyte conduct the electricity? | it has free ions which are able to conduct the electricity |
| which electrode take electrons away and which electrode gives electrons? | positive - takes electrons away negative - gives electrons |
| what is another method of extraction, beside electrolysis and reduction? | displacement - where a more reactive metal is put in a solution of a dissolved less reactive metal compound. This works as the more reactive metal bonds more strongly with the to the non-metal part of the compound and therefore displaces the less reactive metal from the compound |
| why is scrap iron often used in copper displacement reactions? | because the iron is cheaper than the copper (which is very expensive) and the iron doesn't have to be 100% pure |
| what are two different methods of extracting copper from the ground? | bioleaching phytomining |
| what is bioleaching? | where bacteria is used to separate copper from copper sulphate. The bacteria gets energy from the bond between the copper and the sulphur, separating the copper from the ore. The leachate (solution produced) can be filtered to remove the copper |
| what is phytomining? | plants are grown in soil which contains copper. The plants can't use of get rid of the copper so it builds up in the leaves. The plants are harvested, dried and burned, and then the copper is removed from the ash |
| why is recycling metals important? | mining and extracting metals uses a lot of energy and this comes from fossil fuels - recycling only uses a fraction saves money finite amount of resources/ metal reduces land fill |
| what properties do metals have? | strong malleable conduct heat conduct electricity |
| what are the two major problems with metals? | they can corrode when exposed to air and need protecting they can become 'tired' when repeatedly put under stress and strain and metal fatigue can occur where they then break |
| how does an alloy make a metal harder? | the atoms, previously arranged in layers and able to easily slide over one another, are upset by different sized atoms of the other element/s and can therefore not slide over one another as easily = harder |
| what is bronze made of and what is it used for? | copper + tin used for making medals and statues |
| what is cupronickel made of and what is it used for? | copper + nickel used for making 'silver' coins |
| what metals can be added to gold to make it better suited for jewellery? | zinc/ copper/ silver/ palladium and nickel |
| what is a mixture? | two or more elements that are not chemically bonded together |
| what are hydrocarbons? | a chain of hydrogen and carbon atoms |
| how are different hydrocarbon chains fractioned off using a fractional distillation column? | the crude oil is vaporised the gases rise up the column, cooling they condense at their boiling points shorter chains are fractioned off at the top longer chains are fractioned off at the bottom, often not vaporising at all |
| what are alkanes? | single bonds saturated (carbon forms full 4 bonds) CnH2n+2 |
| what are the properties of alkanes? | shorter the molecule the more runny it is the shorter the molecule, the more volatile it is (vaporise at a lower temperature) - lower boiling point shorter the molecule, the more flammable it is |
| why is crude oil so important? | it's our main source of fuel major industry source of raw materials - e.g. chemicals everything is already set up for crude oil easiest and cheapest option for fuel more reliable than alternatives |
| what are the issues involved with crude oil supplies | they're finite - non-renewable we don't know when they'll run out technology is improving allowing us to extract more oil than before takes time to develop new energy sources - even though there are others |
| what are the three main sources of alternate energy that we use? | solar wind nuclear |
| how does crude oil affect the environment? | when it spills it pollutes the water it poisons the animals living in the water it covers their feathers and stops the water-proofing contributes to global warming/ acid rain and global dimming |
| what are the problems with burning fossil fuels? | when a fuel is burnt, carbon dioxide and water vapour are released sulphur impurities also form sulphur dioxide nitrogen oxides form at high temperatures |
| what happens when there is not enough oxygen in the combustion reaction - partial combustion? | solid particles (particulates) of soot (carbon) are released and so is un-burnt fuel carbon monoxide (poisonous) is also relased |
| what happens when sulphur dioxide is released into the atmosphere? | when sulphur dioxide mixes with water vapour in the atmosphere, it forms sulphuric acid this is the same with oxides of nitrogen |
| what are the issues with acid rain? | causes lakes to become acidic and plants and animals die limestone buildings are eroded, along with stone statues acid rain has been linked to health issues |
| how can sulphur emissions be controlled? | sulphur can be removed before the fuel is burnt (expensive) car fuels are being replaced by low-sulphur versions power stations have Acid Gas Scrubbers to take harmful gases out of fumes before they are released |
| how do particles cause global dimming? | particles of soot and ash are produced when fossil fuels are burnt these particles reflect sunlight back into space or help create clouds which also reflect sunlight back |
| what are three alternate fuels used for cars? | ethanol biodiesel hydrogen gas |
| what are the pros and cons of ethanol? | pros = carbon neutral/ only other product is water cons = engines will need to be converted/ not widely available/ will use up crop spaces and therefore increase the price of food |
| how is ethanol made? | plant material (known as bio-fuel) undergoes fermentation - often mixed with petrol to make a better fuel |
| what is bio-diesel? | produced from vegetable oils (rapeseed oil) it is another bio-fuel. It is also mixed with diesel to run a diesel engine |
| what are the pros and cons of biodiesel? | pros = carbon neutral/ engines don't need to be converted/ produces less sulphur dioxide and particulates than normal cons = expensive/ can't make enough to replace diesel/ increases food prices |
| how is hydrogen made? | hydrogen gas can be made through electrolysis of water |
| what are the pros and cons of hydrogen gas? | pros = hydrogen combines with oxygen to form water - clean cons = needs a special expensive engine/ hydrogen isn't widely available/ still requires energy from another source/ hard to store as it is explosive |
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