metals Flashcards
(26 cards)
physical properties
- high density
- good electrical conductivity
- malleable + ductile
- high mp + b.p
metal + dilute acid
those above hydrogen react to form
salt + hydrogen
metal + cold water/steam
- metal hydroxide + hydrogen
(K to Ca) - metal oxide + hydrogen
(Mg to Pb)
metal + oxygen
react up to gold to form
metal oxides
uses of aluminium
- aircraft due to slow density
- cables due to low density + conductivity
- food container due to resistance to corrosion
use of copper
electrical wiring because very good electrical conductivity + ductility
alloy
mixture of a metal with other elements
brass
copper + zinc
stainless steel
iron + carbon/nickel/chromium
alloys stronker because
different sized atoms don’t allow layers to slide
use of stainless steel
- cutlery because hard + resist corrosion
potassium + cold water
- effervescence
- shoots across
- burns with lilac flame
sodium + cold water
- effervescence
- dart across
- melts into ball
calcium + cold water
- effervescence
- sinks to bottom
- water turns cloudy
magnesium + steam
- in boiling tube
- forms white solid
unreactivity of aluminium
oxide layer , reacts of scratched
rust is
hydrated iron (iii) oxide
rust condition
water + oxygen
barrier protections
- painting
- greasing
- plastic coating
galvanising
coated in zinc (barrier + sacrificial)
sacrificial protection
- more reactive than iron
- lose electrons more readily
- react in preference to iron
ease in extracting
more reactive = harder
iron extraction
1) coke burnt to provide heat + produce CO2
C (s) + O2 (g) → CO2 (g)
2) CO2 reacts with more coke to form CO
CO2 (g) + C (s) → 2CO (g)
3) CO reduces iron ore
Fe2O3 (s) + 3CO (g) → 2Fe (I) + 3CO2 (g)
4) limestone decomposes to form CaO
CaCO3 (s) → CaO (s) + CO2 (g)
5) CaO reacts with acidic impurities to form slag
CaO (s) + SiO2 (s) → CaSiO3 (l)
aluminium ore
bauxite
