Studied by 7 people
Which three elements are needed for plant growth?
N, P, K
In what form do fertilisers produce n + p + k?
water soluble ions
What do you react to make ammonium sulphate?
ammonia and sulphuric acid
What type of reaction is ammonia and sulphuric acid?
titration
What should you ensure you final product in a titration for fertilisers does not contain?
indicator, excess acid
What name can you give to small-scale fertilisation production?
batch
What name can you give to large scale fertilisation production?
continuous
Does continuous or batch scaler have a higher cost?
continuous
Does continuous or batch scaler have a higher production rate?
continuous
Does continuous or batch scaler have a higher shut down rate?
batch
Does continuous or batch scaler have a higher workforce?
batch
In which ways can ethanol be made?
fermentation of glucose, hydration of ethene
Give the balanced equation for the fermentation of glucose.
C₆H₁₂O₆₍ₐq₎ → 2O₂₍g₎ + 2C₂H₅OH₍ₐq₎
Where does glucose come from?
plant sugars
What is used to catalyse the fermentation of glucose?
yeast enzymes in cells
What temperature does the fermentation of glucose need to be?
35°C
What are the advantages of fermenting glucose to make ethanol?
low cost/modereate conditions/low energy
Gave the balanced symbol equation for the hydration of ethene.
C₂H₄ + H₂O ⇌ 2C₂H₅OH
Where does ethene come from?
crude oil
At what temperature is the hydration of ethene?
300C
At what pressure is the hydration of ethene?
60 atm
What is the catalyst used in the hydration of ethene?
phosphoric acid
What are the advantages of hydrating ethene to make ethanol?
high rate of reaction/high percentage yeild/high purity/no by-products
What is the percentage yield in hydrating ethene to make ethanol?
95%
What are the disadvantages of hydrating ethene to make ethanol?
high cost/ high conditions(therefore expensive)/ high energy requirement
What product is made in the Haber process?
ammonia(NH₃)
What is the symbol equation for the Haber Process?
What is the word equation for the Haber process?
nitrogen + hydrogen --> ammonia
What are the raw materials of the Haber process?
nitrogen, hydrogen
Where is nitrogen found?
atmosphere
Where is hydrogen obtained from?
reacting methane with steam
What is most of the ammonia used for?
fertilisers
What catalyst is used in the Haber process?
iron
What pressure is used in the Haber process?
200 atmospheres
What temperature is used in the Haber process?
450C
Why is a compromise used in the Haber process?
expensive to achieve high pressures (stronger equipment and more energy needed)
What is made in the Contact process?
sulphuric acid
What are the raw materials used in the Contact process?
sulphur, air, water
What is the word equation for stage 1 of the contact process?
sulphur + oxygen --> sulphur dioxide
What is the symbol equation for stage 1 of the contact process?
S(s) + O₂(g) --> SO₂(g)
What is the word equation for stage 2 of the contact process?
sulphur dioxide + oxygen --> sulphur trioxide
What is the symbol equation for stage 2 of the contact process?
2SO₂(g) + O₂(g) -> 2SO₃(g)
What is the word equation for stage 3 of the Haber process?
sulphur trioxide + water -> sulphuric acid
What is the symbol equation for stage 3 of the Haber process?
SO₃(g) + H₂O(l) -> H₂SO₄(aq)
Which stage of the contact process is in equilibrium?
stage 2
What pressure is used in the contact process?
2 atm
Why is the pressure of 2 atm used in the contact process?
the equilibrium position already lies far right
What temperature is used in the contact process?
450C
Why is the temperature of 450C used in the contact process?
the forward reaction is exothermic but a reasonable rate is needed
What catalyst is used in the contact process?
Vanadium(V) oxide
What is an ore?
a rock/mineral containing enough of a metal compound to make it economical to extract the metal
What is the ore for copper compounds?
malachite
What is the formula for copper compounds?
CuCO₃
What is the ore for aluminium compounds?
bauxite
What is the formula for aluminium compounds?
Al₂O₃
What is the ore for iron?
haematite
What is the formula for iron compounds?
Fe₂O₃
Whar is the name of the process used to extract aluminium?
electrolysis
Why is electrolysis used to extract aluminium?
it is more reactive than carbon
What do copper and iron react with to be extracted?
carbon
What do copper ores typically contain?
CuS (copper sulphate)
What happens in stage 1 in copper extraction?
copper(II) sulphate is roasted in air
What is the symbol equation for stage 1 in copper extraction?
2CuS(s) + 3O₂(g) -> 2CuO(s) + 2SO(g)
What happens in stage 2 of copper extraction?
the copper(II) oxide is heated with carbon
What is the symbol equation for stage two of copper extraction?
2CuO(s) + C(s) -> 2Cu(s) + CO₂(g)
What is reduced in copper extraction?
CuO / copper oxide
What is oxidised in copper extraction?
Cu / copper
What is the reducing agent in copper extraction?
C / carbon
How is iron extracted from its ore?
blast furnace, by reducing iron oxide with carbon
What is 'coke'?
carbon, coal
What happens in stage 1 of iron extraction?
coke burns in hot air
What is the symbol equation for stage 1 of iron extraction?
C(s) + O₂(g) -> CO₂(g)
What happens in stage 2 of iron extraction?
more coke reduces CO₂ to CO
What is the symbol equation for stage 2 of iron extraction?
CO₂(g) + C(s) -> 2CO(g)
What happens in stage 3 of iron extraction?
CO reduces the Fe₂O₃ at 1500C
What is the symbol equation for stage 3 of iron extraction?
3CO(g) + Fe₂O₃(s) -> 3CO₂(g) + 2Fe(l)
What is used to purify iron?
limestone (CaCO₃)
What are the two stages of purifying molten iron?
thermal decomposition, slag formation
What is the symbol equation for thermal decomposition?
CaCO₃(g) -> CaO(s) + CO₂(g)
What is the symbol equation for stage two of purifying molten iron?
CaO(s) + SiO₂(s) -> CaSiO₃(l)
What is aluminium oxide dissolved in before extraction?
molten cryolite
Why is aluminium oxide dissolved in cryolite before extraction?
reduces melting point temperaturre
What happens at the cathode when iron is extracted?
reduction
What is the half equation at the cathode in aluminium extraction?
Al3+ + 3e- -> Al
What is the half equation at the anode in aluminium extraction?
2O2- -> O₂ + 4e-
How can metals be extracted biologically?
bioleaching, phytoextraction
What type of ores is biological extraction typically used for?
low grade ores
How is thw metal extracted from the plants grown on ores?
absorbption of metal ions(sometimes complexing agent used). the plants are then harvested and burnt and the ash is used to extract the metal by electrolysis or reacting with carbon
What are the advantages of using bacteria to extract metals?
low energy (therefore cheaper)
What are the disadvantages of using bacteria to extract metals?
slow / can release toxic waste into water ways and soil
What is an alloy?
a mixture of two or more elements, at least one of which is a metal
What are the physical properties of steel?
strong
What is steel used for?
buildings, bridges, cars
What is duralumin?
alloy of aluminium and copper
What are the properties of duralumin?
lightweight
What is duralumin used for?
aircraft parts
What is solder?
alloy of tin and lead
What are the properties of solder?
low melting point
What is solder used for?
Joining electrical wires
What is brass?
alloy of copper and zinc.
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