C6.1

Question 1

What elements do plant need and why are fertilisers used form
What is phosphate

What are fertilster called with all three of these

Answer 1

1) nitrogen, phosphorus , potassium
An absence of these will show poor root /fruit growth and discoloured leaves. Mineral defence has leads to lower quality yield and less.

Fertilisers replace them, roots cns only take them up if they are in water-soluble form so nitrate phosphate and potassium ions

Po4-3

3)NPK fertilisers

Question 2

What is the haber process ?

How are the raw materials extracted

Answer 2

Haber process manufactures ammonia , from nitrogen and hydrogen

Raw materials are air natural gas and steam

• nitrogen manufactured from fractional distillation if liquified air (67% nitrogen)
• hydrogen is manufactured by reacting natural gas (methane) with steam

Question 3

What do fertilster factories make with this ammonium and why?

Answer 3

Ammonia being a base can neutrales acids to give fertilisers

-ammonia with nitric acid = ammonium nitrate
- phophouric acid = amonnium phosphate
- sulfur ich acid = ammonium sulfate
And potassium chloride with the ammonium nitrate= potassium nitrate

These are all fertilisers that are needed for plants (made by haber process ammonium with acid , also made by contact process)

Question 4

How to make potassium sukfste in the lab?

Titration neutralisation

Answer 4

1) titration between dilute POTASSIUM hydroxide solution and sulfuric acid
2) koh is in the conical flask and add phenolphthalein,
3) put sulfuric acid in Bureete , add some swirl, and stop when indicator changes form link to colourless
4) this is end point, become neutral now
5) need to extract the indicator, so add activated charcoal ( attracts phenolphthalein), and now you can FILTER to remove activate charcoal with indicator

6) now need to evaporate water and potsssium sulfate , but don’t dry it too much…

Summary

1) titration with KOH and H2So4 both dilute
2) use activate charcoal to attract phenolphthalein
3) filters to remove this
4) warm to evaporate water from potassium sulfste but not heat to dryness

Question 5

How to make ammonium sukfste in the lab?

(Titration with ammonia and acid )

Dangers of ammonia ?

Answer 5

1) ammonia dilute in clinical flaks. Add METHYLL ORANGE indicator here , which orange in alkali and red in acid
2) put sulfuric acid solution dilute in brütet and add slowly until end point swirl Esch time. When yellow to red , stop
3) add more amonnia because ammonia releases some gas which is IRRATATING SHARP SMELL, so this ensures all is reacted (left over will just evaporate)

4) not pure, so need to do it again without indicator.
5) then crystallise and filter crysslts of ammonium sulfste

Summary

1) titration of ammonia solution and sulfuric acid. METHYLL orange indicator (orange alkali red in acid)
2) do it again but remove indicator . Crystallise and filter crystals

3) ammonia solution release some gas which is sharp irreging so need tk be careful , can react a bit excess too

Question 6

School lab vs industry production?

Batch vs continuous 5 fsctord comparison ?

Answer 6

School = batch (small amount at a time), industry continuous (large all the time )

Batch production, cost and ease of automation is low. The workers needed is large and shut down periods are frequent

Whereas continuous high production rates, but cost but also high ease of automation. Although costly numbers of workers are low, shut down periods are rare.

Question 7

Haber process conditions chosen ? (4)
Why tho?
N2 + 3H2 —> 2NH3

Answer 7

It is a reversible reaction so le Chat Leier in considertaion here

1) pressure or 200 ATM
- increase pressure= moves to the right, which is good, but increasing it too high would be HAZARDOUS and expensive, so more yield is not justify Addison so costs, so compromise

2) temp of 450
- forward reaction is exothermic so increase = lower yield. Thus it is low enough for decent equilibrium yield but high enough for good rate of reaction
- also catalyst only works efficiently above 400°C

3) an iron catalyst - obvious
4) normal yield under these is 30%, but as mixture of gases that are leaving the vessel are cooled , ammonia is liquified , but nit hydrogen or nitrogen excess. Thus ammonia can be extracted and unreacted hydrogen and nitrogen to be recycled , so overall yield is now 97%

Question 8

Haber process conditions

Answer 8

1) 200 atm (hazardous )
2) 450 temp (forward exothermic , catalyst)
3) iron catalyst
4) to liquify the ammonia exiting so unrescted h2 + n2 can be recycled = 97% yield now

Question 9

What is the contact process and what is it used for
What are the three raw materials and what are the two stages of making sulfuric acid

Which stage is the contact process and reversible only stage?

Answer 9

Used for making SULPHURIC ACID , and reversible resction only in stage 2

2) sulfur air (source of oxygen ) and water is used to make sulfuric acid

In stage 1:
Sulfur Burns in air to produce sulfur dioxide (sulfur + oxygen -> sulfur dioxide
2:
Sulfur dioxide + oxygen —>sulfur trioxide
3 sulfur trioxide + water—> sulfuric acid

Stage 2

Question 10

What conditions are chosen for the contact process? STAGE 2 REMEMBER

Answer 10

1) 2 atm
2) 450 °C
3) vanadium oxide catalyst v2o5

Question 11

Why is the pressure and temp chosen in contact process

For temp what is needed for vandium oxide

Answer 11

2SO2+ O2–>2SO3

Question 12

What hazard are there in contact process and how controlled

2 stages, what is chemical formula for oleum and you can work it out

Answer 12

Stage 3 reaction between sulfur trioxide snd water is so ectothermic they iron produced s hazardous mist of acid , so stage 3 is carried out in two steps

1) sulfur trioxide is passed through concentrated sukfiruic acid made before to make oleum
H2so3 +so3-> h2s2o7

2) oleum added to water and this makes larger volume of concentrated sulfuric acid
H2s2o7 + h2o —> 2H2SO4

Question 13

How is alcohols like ethanol made from renewable material
What renewable
What conditions set

Answer 13

Renewable can be replaced and should not run out , using FERMENTATION.
Carrie dour by single cell fungi called yeast that contain non corrosive enzymes that catalyst conversion of glucose into carbon dioxide and ethanol (biology)

Yeast becomes inactive if temp too low and denatured if above 50, so it kept at 35 and standard atm, same used in industry but more complex equipment .

Question 14

How is ethanol alcohol made from non renewable material?
What non renewable

What three conditions needed such that csn’t be made in classs

Answer 14

Non renewable raw materials are used faster than replaced, such that they will run out one day if keep using them

Here ETHENE obtained from fractional of crude oil (non-r), and hydration (water) makes ethanol

Ethene + steam ->(reversible) ethanol

needs 300°

• 60atm
• phosphoric Acid catalyst (corisive )

Question 15

What are differences between hydration and fermentation to produce ethanol

What are the percentage yields

Answer 15

Fermwntion low costs, normal consisted, low energies, ut low rate of reaction, percentage yield of 15% and pure= has to be filtered and fractional distilled .

Uses natural catalyst and batch. Renerwbsle tho

But hydration is high cost, high temp and pressure, high rate of reaction , high yield 95% and highly pure (no by products).

Uses corossive catalyst and continuous . Non renewable tho

Manufacturer go for the one more profitable, or more environmental

Question 16

What is an ore ?
What three ores are there and what give they ?

Hoe do we get pure metal

Answer 16

A rock or mineral thst contains enough metal / metal compijdnro make it economical to extract it- the value of the metal is more then the cost of extracting it

Malachite = copper carbonate 
Bauxite = aluminium oxide
Haemite= iron(111) oxide 

Has to be mined and then separate the metal compound from the ore, then extracted from metal compound

Question 17

How are metals extracted from compounds in theory

How done instead , more reactive than carbon and less, and why?

Answer 17

All metals can be extracted from conlunds usinf electorkhsis but electricity is expensive

If metal less reactive then carbin, cheaper smithies such as heating iron and copper with carbon or carbon monoxide used instead. This is because carbin here reduces another metal, but only if that is less reactive then itself…

If higher than carbon , ELECTROLYSIS MUST BE USED

Question 18

How to extract copper from copper Sulfide

How to do copper oxide really
Practical of lab extracting copper from copper oxide with charcoal?

Answer 18

1) “roast “ the copper Sulfide
Copper sulfide + oxygen = copper (11) oxide and sulfur dioxide

2) then copper oxide is reacted with carbon = copper and carbon dioxide

Here carbon reduces copper oxide , carbon getd oxidises is = REDOX

QUICK PRACTICL

1) mix charcoal (carbon) with copper oxide in a crucible , keep lid on so csn’t escape powder and air doesn’t come in and burn carbon
2) heat
3) come back let it cool, then transfer into water, copper sinks and excess charcoal floats. You can separate it

Excess used to ensure all of copper oxide is used

Question 19

What is a blast furnace (dimensions and output) and what 4 things are used in extracting iron ?

Answer 19

Blast furnace a large reaction container used to extract iron ore. Modern furnace 30 kmhigh and produce 10k tonnes per day

Material :

1) iron ore such as haematite (iron 3 oxide)
2) coke (carbon , made by heating coal without air)
3) limestone purify iron
4) Hot air at bottom of furnace

Question 20

Three stages of reduction to get iron?

What temp must it be for carbon monoxide to reduce iron 3 oxide to iron (stage 3)

Answer 20

Carbon can be used by carbon monoxide main reducing agent , so this has to be made first
1) coke burns in HOT AIR, to make co2
C+ o2= co2
2) coke reduces more Cabrini’s dioxide to make Monoxids
C + co2= 2co
3) carbon monoxide reduces iron(3) oxide to produce iron ONLY AT 1500°. This is this haematite
3Co+ Fe2O3= 3Co2 + 2Fe

Next it gets purified

Question 21

How does iron get purified ?

What are impurity’s in iron ore call sandy

What is calcium silicate

Answer 21

The molten iron trickled down the furnace but fins fins Sandy impurities from iron ore. Limestone calcium carbonate can get rid
1) calcium carbonate decomposed in high temps to make calcium oxide
Caco3 = can + co2
2)calcium code formed reacts with silica found in sandy impurity’s if snd to from calcium silicate
CaO + SiO2 = CaSiO3

This molten calcium silicate is known as slag. It will float on top of the iron and so these are separated by being removed …

Question 22

Bauxite is aluminium oxide , how can it be extracted?

What is problem and what is solution to it (what normal temp and after temp with cryolite )

Answer 22

Bauxite cintisjs natural aluminium, and as more reactive than carbon must be electrolysed. However melting pint ridiculously high and does not dissolve in water, so…

Melting point is normally 2000°C= too expensive
Thus
Allumnium oxide is dissolve in molten CRYOLITE
- chrolite much lower melting point then aluminium oxide and allows electrolysis to happen at 950°C

Question 23

How is now dissolved aluminium oxide in the cyrolite electrokysed !

What is structure of electrolysis cell? (Material)
What is produce at each electrode and what specific about anode ?

Answer 23

Stell lined with graphite to make cathode
Large graphite blocks series makes anodes

Alumium is produce at cathode (low so that it can trickle and leave)
Oxygen is produced at anode .
As high temps it can react with the carbon in graphite and produce carbon dioxide too

In between is the molten electroyte if alumium oxide dissolved in cyrolite

Question 24

What is acid mine drainage (basis of biolesching )

Answer 24

When mines are abandoned they are flooded.
Metal Sulfides oxidise underwater to produce sulfuric acid
This acid then reacts with other metals producing soluble metal ORES compounds , which leave as the water drains and leaves too

However some bacteria can cause this to happen faster= biolesching

Question 25

So then how does biolesching work to separate say copper from copper sulfide in ores

Answer 25

• bacteria oxides iron (II) and sulfide ions and USE ENERGY mad ein process (like respiration), they use energy by breaking binds etc
• thus sulfuric acid now forms in the presence of water and oxygen
• this breaks down copper sulfide ores and others, releasing copper ions and others the can be extracted later .(by electrolysis eg)

Question 26

What are pro and con to biolesching
(Low grade ores are?)
4+
2-

Answer 26

+cheaper than trsdionsl mining and processing
+ allows for metals to be extracted from ores that contain too little metal for trsdionsl metals to be profitable- LOW GRSDE ORES
+bacteria occur naturally and no special treatment
+do not release harmful sulfur dioxide into air

• slow
• toxic substance sometime produced,
• need to be carful it don’t go into snd SULFUIC ACID into water supplies and soil…

Question 27

How phytoextrsction work

Process of using plants to extract low grade ore

Answer 27

• plants can absorb dissolved ions through roots , and some better than others. They csn’t use or get rid of these ions, so they just build up in leaves etc
• thus a crop is planted in soil contains low grade ore or mine waste
• complexing agent added so they can absorb more easily
• harvested and BURNT to ash= high concentration of ore
• can then be extracted as if it was normal ore like electrolysis etc

Question 28

What are pro and con for phytoextrstcion

4+
2-

Main negative for these biological methods is just slow
Main advantage is less waste and damage to environment

Answer 28

+cheaper again than trsdionsl mining processing
+less waste and involves smaller energy transfers
+ process is carbon neutral, absorb carbon dioxide in photosynthesis but also release when burnt
+ when being burnt can be used for electricity production

• just really slow
• ethical?