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55 Cards in this Set

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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

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

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

what's reduction

the loss of oxygen from a substance


eg cooper oxide +hydrogen --> copper + water

what's oxidation

the gain of oxygen by a substance


eg magnesium + oxygen --> magnesium oxide

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

what are alloys

made by mixing a metal with another material to improve properties

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

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

what does the metal used to extract metals depend on

the reactivity of the metal and how stable the ore is

how much energy is needed to reduce reactive metals

a lot

how much energy is needed to extract unreactive metals

not a lot

which metals are extracted by electrolysis

potassium


sodium


calcium


magnesium


aluminium

which metals are extracted by carbon or carbon monoxide

zinc


iron


Tin


lead

what metals are extracted by various chemical reactions

copper


silver


gold


platinum

how are most metals extracted

from ores found in the earths crust

how are u reactive metals found

in the earth as u combined elements

what reaction is rusting

an oxidation reaction - iron and steel rust when they come into contact with water and oxygen = corrosion

what does iron water and oxygen form

hydrated iron (III) oxide


we see this as rust

the more reactive the metal the more

rapidly it corrodes

why doesn't gold corrode at all

because metals with low reactivity are more resistant to corrosion and oxidation

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

1st benefit of recycling metals

natural reserves of metal ores will last longer if more metals are recycled

2nd benefit of recycling metals

for most metals less energy is needed to recycle than is needed to extract from their ores

3rd benefit of recycling metals

recycling reduces the need to mine ores. mining damages landscapes and creates noise and pollution

4th benefit of recycling metals

more recycling means less waste metals are disposed in land fill sites

last benefit of recylying

recycling produces less pollution eg sulfur dioxide

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.

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.

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

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.

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

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

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.

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

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

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

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.

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

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

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

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

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.

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

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

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

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

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

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.

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

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

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

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

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

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.