C 15 Using our resources Flashcards
conditions for rusting
both air and water needed
preventing rust
providing barrier between iron and air oxygen
1. paint
2. oil grease
3. plastic
4. less/more reactice metal
protecting iron with zinc (more reactive)
iron galvanised, sacrificial protection fro zinc to ptotect iron, even when iron is exposed to water and air
characteristics of alloys
harder than pure metals becasue layers are disorted by differently sized atoms, so they don’t slide.
mixture and formulation
copper alloy
copper with tin. broze to make statues, resistant to corrusion
brass+copper= brass qhich is harder, used for musical instruments
Al alloys
al low densities, many diff alloys can be made.
eg. aircraft
gold alloys
gold+copper=jewellery
pure gold wears away to easily, varying proportions allows to get diff shades of gold
percentage of gold in alloys
divide n carat by 24 x 100
diff steels
High carbon steel
low carbon steel=soft easily shaped
stainless steel=chronium-nickel, don’t rust, hard resistant, eg cooking utensiles, cutlery, in chemical insustry
what happens when you heat thermosetting polymers
don’t melt
materials of sand
sand, limestone, sodium carbonate
types of glass
soda-lime=sand,sodium carbonate, calcium carbonate
borosilicate= sand, boron trioxide, melt at higher p.
all mixet together at heated at high temp
clay ceramics
hard, unreactive, resistant to heat
wet clay is baked in furnace
eg. briks, ceramig mugs, plates, crockery
what are composites
made of 2 maerials.
have reinforcement (fibres, fragments) in Matrix (binds them together)
fibre-glass composite
reinforcement= glass fibres
matrix=polymer
lighter,malleable.
cars
natural wood composite
reinforcement=wood fibres
matrix=lignin
Plywood
reinforcement=wood fibres
matix= grain (maybe)
carbon fibre composite
reinforcement= C fibres/nanotubes
matrix= polymer
eg. sports equipment, tennis rackets
raw materials for production of ammonia
nitrogen from air
hydrogen from natural gases(methane + steam)
catalyst of haber process
iron
temp + pressure haber process
200 atm
450 C
uses of ammonia
85% fertilisers
structure of NH3
covalent bonding
reaction of haber process is
reversible
how is ammonia removed
by cooling down the gases so that ammonia liquifies, unreacted nitrogen + H are recycled
formula of haber process
N2 + 3h2 = 2NH3
what would higher pressures cause in ammonia
produce more ammonia but it wold be too expensive to run as it favours the side with least amount of moles, equilibrium moves to the right
effects high/low temp
equilibrium moves to tthe left as reaction favours endothermic reaction. Less ammonia would be made.
Low temp. would produce more ammonia but too slowly.
what are the conditions in haber process
compromises
what is ammonia aso used for
to make ammonium nitrate fertiliser, if added to nitric acid
how can other solid fertlisers salts can be made
reacting ammonia (an alkali) with different acids)
2 neutralisations of ammonia
ammonia +sulfuric acid-> ammonium sulfate (salt)
ammonia + phosphate -> ammoium phosphate(can be made using titration)
why are fertlisers used
to supply nitrogen, phosphorus and potassium to plants
what is NPK
mixtures of compounds so that N, P and K can be added to land at same time
where does nitrogen come from and what is iy reacted with
from ammonia, reacted with acids to maked fertilisers
eg ammonium sulfate, ammonium nitrate
source of phosphorus
phosphate rock, which is mined
what happens to phosphate rock
treated with acids to form fertilisers
eg. ammonium phosphate, calcium phosphate
where does potassium comes from
potassium salts which are mined
potassium fertilisers examples
potassium chloride, potassium sulfate
