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55 Cards in this Set
- Front
- Back
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name a biofuel and discuss how it is made |
ethanol is made by fermentation. this converts sugar from sugar canes or sugar beets into ethanol or carbon dioxide. it can reduce the demand for petrol and enzymes in yeast help it happen |
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advantages of bio fuels |
1) renewable 2) carbon neutral: releases the same amount of carbon dioxide when they burn as is used to make oil for photosynthesis. this reduces global warming |
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disadvantages of bio fuels |
1) growing crops to make bio fuels requires land and may affect availability of the land for growing food 2) may not be ethical to use food crops in this way; could give to hungry peolle |
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what's reduction |
the loss of oxygen from a substance eg cooper oxide +hydrogen --> copper + water |
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what's oxidation |
the gain of oxygen by a substance eg magnesium + oxygen --> magnesium oxide |
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uses of calcium oxide |
neutralise soil acidity add water and a reaction happens forming calcium hydroxide calcium hydroxide soluble in water and forms limewater which tests Co2 calcium carbonate used to remove acidic gases from coal fired power station chimneys |
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what are alloys |
made by mixing a metal with another material to improve properties |
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why do alloys help |
in a pure metal the layers of atoms can slide over each other. an alloy is stronger because the different sized atoms joe up the structure and stop the layers sliding |
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why is iron good for alloying |
iron is alloyed with other metals to produce alloy steels with a higher strength and better resistance to corrosion |
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what does the metal used to extract metals depend on |
the reactivity of the metal and how stable the ore is |
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how much energy is needed to reduce reactive metals |
a lot |
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how much energy is needed to extract unreactive metals |
not a lot |
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which metals are extracted by electrolysis |
potassium sodium calcium magnesium aluminium |
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which metals are extracted by carbon or carbon monoxide |
zinc iron Tin lead |
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what metals are extracted by various chemical reactions |
copper silver gold platinum |
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how are most metals extracted |
from ores found in the earths crust |
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how are u reactive metals found |
in the earth as u combined elements |
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what reaction is rusting |
an oxidation reaction - iron and steel rust when they come into contact with water and oxygen = corrosion |
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what does iron water and oxygen form |
hydrated iron (III) oxide we see this as rust |
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the more reactive the metal the more |
rapidly it corrodes |
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why doesn't gold corrode at all |
because metals with low reactivity are more resistant to corrosion and oxidation |
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how are the new materials of alloys used |
to fit new applications like the creation of new shape memory alloys in spectacle frames and are stents in damaged blood vessels |
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1st benefit of recycling metals |
natural reserves of metal ores will last longer if more metals are recycled |
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2nd benefit of recycling metals |
for most metals less energy is needed to recycle than is needed to extract from their ores |
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3rd benefit of recycling metals |
recycling reduces the need to mine ores. mining damages landscapes and creates noise and pollution |
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4th benefit of recycling metals |
more recycling means less waste metals are disposed in land fill sites |
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last benefit of recylying |
recycling produces less pollution eg sulfur dioxide |
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give an example of how alloying changes the properties of megals |
nitinol is an alloy of nickel and titanium. it is a smart material. these materials have a property that changes with a change of conditions. usually temperatures. |
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give an example of how alloying changes the properties of megals |
nitinol is an alloy of nickel and titanium. it is a smart material. these materials have a property that changes with a change of conditions. usually temperatures. |
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what does it mean by nitinol is a shape memory alloy |
if the shape of something made of nitinol is changed it returns to its original shape when heated |
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give an example of how alloying changes the properties of megals |
nitinol is an alloy of nickel and titanium. it is a smart material. these materials have a property that changes with a change of conditions. usually temperatures. |
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what does it mean by nitinol is a shape memory alloy |
if the shape of something made of nitinol is changed it returns to its original shape when heated |
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how and why is gold made into an alloy |
pure gold is too soft for jewellery. silver and copper is added to it to make it harder and stronger. purity of gold is measured in carats or as fineness. fineness is 1000 parts per thousand |
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give an example of how alloying changes the properties of megals |
nitinol is an alloy of nickel and titanium. it is a smart material. these materials have a property that changes with a change of conditions. usually temperatures. |
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what does it mean by nitinol is a shape memory alloy |
if the shape of something made of nitinol is changed it returns to its original shape when heated |
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how and why is gold made into an alloy |
pure gold is too soft for jewellery. silver and copper is added to it to make it harder and stronger. purity of gold is measured in carats or as fineness. fineness is 1000 parts per thousand |
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how are iron and steel used in relations to their propertied |
pure iron is too soft to be useful so it's made to steel which is harder and stronger. steel is used to make bridges card electrical goods and machinery |
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give an example of how alloying changes the properties of megals |
nitinol is an alloy of nickel and titanium. it is a smart material. these materials have a property that changes with a change of conditions. usually temperatures. |
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what does it mean by nitinol is a shape memory alloy |
if the shape of something made of nitinol is changed it returns to its original shape when heated |
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how and why is gold made into an alloy |
pure gold is too soft for jewellery. silver and copper is added to it to make it harder and stronger. purity of gold is measured in carats or as fineness. fineness is 1000 parts per thousand |
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how are iron and steel used in relations to their propertied |
pure iron is too soft to be useful so it's made to steel which is harder and stronger. steel is used to make bridges card electrical goods and machinery |
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how's aluminium used in relation to its propertied |
doesn't corrode because it had a layer of aluminium oxide that forms quickly on its surface so used to make aeroplanes |
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give an example of how alloying changes the properties of megals |
nitinol is an alloy of nickel and titanium. it is a smart material. these materials have a property that changes with a change of conditions. usually temperatures. |
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what does it mean by nitinol is a shape memory alloy |
if the shape of something made of nitinol is changed it returns to its original shape when heated |
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how and why is gold made into an alloy |
pure gold is too soft for jewellery. silver and copper is added to it to make it harder and stronger. purity of gold is measured in carats or as fineness. fineness is 1000 parts per thousand |
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how are iron and steel used in relations to their propertied |
pure iron is too soft to be useful so it's made to steel which is harder and stronger. steel is used to make bridges card electrical goods and machinery |
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how's aluminium used in relation to its propertied |
doesn't corrode because it had a layer of aluminium oxide that forms quickly on its surface so used to make aeroplanes |
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how's gold used in relations to its propertied |
used for jewellery as its attractive and remains shiny because it doesn't tarnish from corrosion. good electrical conductor, used in phones and computers. used in printed circuit boards and connection strips and contacts in switches |
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give an example of how alloying changes the properties of megals |
nitinol is an alloy of nickel and titanium. it is a smart material. these materials have a property that changes with a change of conditions. usually temperatures. |
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what does it mean by nitinol is a shape memory alloy |
if the shape of something made of nitinol is changed it returns to its original shape when heated |
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how and why is gold made into an alloy |
pure gold is too soft for jewellery. silver and copper is added to it to make it harder and stronger. purity of gold is measured in carats or as fineness. fineness is 1000 parts per thousand |
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how are iron and steel used in relations to their propertied |
pure iron is too soft to be useful so it's made to steel which is harder and stronger. steel is used to make bridges card electrical goods and machinery |
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how's aluminium used in relation to its propertied |
doesn't corrode because it had a layer of aluminium oxide that forms quickly on its surface so used to make aeroplanes |
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how's gold used in relations to its propertied |
used for jewellery as its attractive and remains shiny because it doesn't tarnish from corrosion. good electrical conductor, used in phones and computers. used in printed circuit boards and connection strips and contacts in switches |
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how is cooper used in relation to its properties |
good electrical conductor, electrical cables are made from copper. copper has low reactivity and doesn't react with water so ideal for water pipes. |
