metals Flashcards
list 3 physical properties of metals?
- conducts heat and electricity
- high melting and boiling point
- malleable and ductile
list 3 chemical properties of metals?
- reacts with water
- reacts with acid
- reacts with oxygen
what are the products of reacting a metal with cold water?
metal hydroxide + hydrogen
what are the products of reacting a metal with steam?
metal oxide + hydrogen
what are the products of reacting a metal with HCL?
a salt + hydrogen
what are the products of reacting a metal with oxygen?
a metal oxide
define an alloy
a mixture of 2 metals, or one metal and one non metal
list 3 properties of alloys that are different from the original metals?
it is harder
more resistant to corrosion
has a greater melting and boiling point
why are alloys harder than their original elements?
the combination of different atom sizes together alters the regular arrangement thus it is more difficult to cut through
what combines to produce brass?
zinc + copper
what is the use of alloy of iron + tungsten?
resistant to high temperatures and are hard
what is the use of alloy of iron + chromium/nickel?
resistant to corrosion
list the reactivity series
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what are the products of thermal decomposition of metal hydroxides/carbonates?
metal oxide + water
does group 1 metal hydroxides undergo thermal decomposition, and why?
no, except for lithium. they have high thermal stability
does group 1 metal carbonate undergo thermal decomposition, and why?
no, except for lithium. they have high thermal stability
what are the products of heating group 1 metal nitrates?
metal nitrite + oxygen
what are the products of heating any metal nitrate (except group 1 metals)?
metal oxide + oxygen + nitrogen dioxide
why doesn’t aluminium react with water and acid?
it reacts firstly with oxygen in the air to form an unreactive protective layer of aluminium oxide around it to prevent any reactions
write a balanced chemical reaction of thermal decomposition of nitrogen nitrate
2NaNO3 → 2NaNO2 + O2
write a balanced chemical reaction of thermal decomposition of copper nitrate
2Cu(NO3)2→ 2CuO + 4NO2 + O2
which process is used to extract metal above carbon in the reactivity series?
electrolysis
what is the ore of iron called?
hematite Fe2O3
what are the raw materials used to extract iron?
coke, hematite, limestone and air
list all the chemical reactions which take place in the extraction of iron from its ore hematite
- C + 02 → CO2 (releases heat)
- CO2 + C → 2CO (monoxide is toxic and must be removed)
- Fe2O3 + 3CO → 2Fe + 3CO2
- CaCO3 → CaO + CO2
- CaO + SiO2 → CaSiO3
why is limestone added to the furnace in the extraction of iron?
to remove impurities
what is slag in the process of extracting iron?
CaSiO3
where is the iron kept when it is converted into steel?
tilting furnace
what is added to convert iron into steel?
oxygen + calcium oxide
why is oxygen added to iron in the process of its conversion to steel?
to oxidise carbon, suplhur, silicon and phosphorus impurities.
- CO2 and SO2 can escape the furnace as gases.
- SiO2 reacts with CaO to produce CaSiO3 slag
what is iron alloyed with to produce stainless steel?
20% chromium and 10% nickel
what is stainless steel used in?
cutlery and sinks
what is the most important property of stainless steel?
resistant to corrosion and strong
what is iron alloyed with to make tungsten steel?
5% tungsten
what is tungsten steel used in?
edges of cutting tools
what is the most important property of tungsten steel?
its hard
what is iron alloyed with to make maganese steel?
13% maganese
what is maganese steel used for?
drill bits
what is the most important property of maganese steel?
its very tough
which process is used to extract aluminium?
electrolysis
what is the ore of aluminium?
bauxite Al2O3
why is cryolite mixed with bauxite in the extraction of aluminium?
to decrease its melting point and increase conductivity
what is the reaction on the negative electrode (cathode) in the extraction of aluminium?
Al3+ + 3e- → Al
what are the 2 reactions at the positive electrode (anode) in the extraction of aluminium?
2O2- - 4e- → O2
C (s) + O2 → CO2
what is the ore of zinc?
zinc blende ZnS
list all the reactions in the process of extracting zinc from its ore
- 2ZnS + 3O2 → 2ZnO + 2SO2
- C + O2 → CO2
- CO2 + C → 2CO (CO2 is the reducing agent)
- ZnO(s) + CO(g) →Zn(g) + CO2(g)
list 2 uses of zinc
- galvanisation
2. to make brass
list 4 uses of aluminium and a reason for it
- aeroplane bodies - low density
- overhead power cables - conducts electricity
- saucepans - conducts heat
- food cans - resistant to corrosion
list 2 uses of copper and a reason for it
- electrical wires - conducts electricity
2. water pipes - unreactive with water
