C6.1

Question 1

What are the 3 useful elements for plants

Answer 1

Nitrogen

Phosphorus

Potassium

Question 2

What does nitrogen deficient in plants do

Answer 2

Delayed growth

Yellow leaves

Question 3

What does phosphorus deficient in plants do

Answer 3

Discoloured leaves, poor root growth

Question 4

What does potassium deficient in plants do

Answer 4

Poor fruit growth and discoloured leaves

Question 5

What does tha haber process do

Answer 5

Produces ammonia

Question 6

Haber process equation

Answer 6

N₂(g) + 3H₂(g) ⇌ 2NH₃(g)

High pressure BUT compromise needed as it can be unsafe and expensive

Low temperature BUT compromise needed as it can decrease ROR

IRON CATALYST

Question 7

How to make fertilisers

Answer 7

Titration

Method 1)
Take a sample every cm3 onto litmus paper to see if it neutralised without indicator

Method 2)
Repeat twice, once with indicator and once without

Method 3)
Use activated charcoal to bind to phenolphthalein then filter

Then just evaporate water

Question 8

What does the contact process do

Answer 8

Make sulfuric acid

Question 9

Stage 1 of contact process

Answer 9

Suffer + oxygen -> sulfuric acid

S + O2 -> SO2

Question 10

Stage 2 of contact process

Answer 10

2SO2 + O2 (reversible arrow) 2SO3

Sulfur dioxide + oxygen = suffer trioxide

Question 11

Stage 3 of contact process

Answer 11

You have a mini step first

Sulfuric acid + sulfate trioxide -> oleum

H2SO4 + SO3 -> H2S2O7

Then

H2S2O7 + H2O -> 2H2SO4

Oleum + water -> sulfuric acid

Question 12

Rules for stage 2 of contact process

Answer 12

Temperature:A compromise temperature of about 450°C is used because the reaction is exothermic, so lower temperatures increase yield but would make the reaction too slow.

Pressure:A low pressure of around 1–2 atm is used because there is little change in the number of gas molecules, so higher pressure would not significantly increase yield.

Catalyst:Vanadium(V) oxide is used to increase the rate of reaction by helping the system reach equilibrium faster without changing the position of equilibrium

Question 13

What are the three main ores you extract metals from?

Answer 13

Malachite - copper carbonate - copper
Bauxite - aluminium oxide - aluminium
Haematite - iron III oxide - iron

Question 14

When would you use electrolysis to extract metals?

Answer 14

When the metal is above carbon in the metal reactivity series

Question 15

When would you use the thermal decomposition to extract metal from its compound?

Answer 15

When the metal is less reactive than carbon

Question 16

What is the metal reactivity series?

Answer 16

Potassium
Sodium
Calcium
Magnesium
Aluminium
Carbon
Zinc
Iron
Tin
Lead
Hydrogen
Copper
Silver
Gold

Question 17

Why is extracting copper a redox reaction

Answer 17

Copper oxide looses oxygen

Carbon gains oxygen

Question 18

Practical method to exctract copper from malachite

Answer 18

You need a crucible, Bunsen burner, and heatproof mat

Add copper oxide into the crucible then add carbon in the form of graphite

Mix and heat

After some time of healing let the crucible cool down

Add contents to water so the unreacted carbon and Chai come to surface

Question 19

What is Stage 2 of iron extraction in the blast furnace?

Answer 19

Carbon dioxide reacts with hot carbon to form carbon monoxide

Question 20

What is the equation for Stage 2 of iron exctrsction

Answer 20

CO₂ + C → 2CO

Question 21

What is Stage 3 of iron extraction in the blast furnace?

Answer 21

Carbon monoxide reduces iron(III) oxide to iron.

Question 22

What is the equation for Stage 3 of iron exctrsction

Answer 22

Fe₂O₃ + 3CO → 2Fe + 3CO₂

Question 23

What is Stage 4 of iron extraction in the blast furnace?

Answer 23

Limestone thermally decomposes to form calcium oxide.

Question 24

What is the equation for Stage 4 of iron exctrsction

Answer 24

CaCO₃ → CaO + CO₂

Question 25

What is Stage 5 of iron extraction in the blast furnace?

Answer 25

Calcium oxide reacts with silicon dioxide impurities to form slag.

Question 26

What is the equation for Stage 5 of iron exctrsction

Answer 26

CaO + SiO₂ → CaSiO₃

Question 27

What is put into the blast furnace of iron exctrsction

Answer 27

Iron ore Coke Limestone

Question 28

What happens at the cathode on electrolysis aluminium oxide

Answer 28

Al3+ + 3e- -> Al Aluminium is produced at the cathode and is reduced

Question 29

What happens at the anode on electrolysis aluminium oxide

Answer 29

2O2- -> O2 + 4e- Oxygen is produced at the anode and is gained

Question 30

How to electrolyse aluminium oxide

Answer 30

It has a really high melting point so in order to lower it yiu mix cryolite with the ore to reduce the melting point

Question 31

Why do you have to constantly change the anode in electrolysis of aluminium oxide

Answer 31

Because the oxygen reacts with the carbon electrodes and makes carbon dioxide

Question 32

List of alloys

Answer 32

Steel Duralumin Solder Brass Bronze

Question 33

What is steel made of and used for

Answer 33

Iron Used for bridges, buildings and cars

Question 34

What is duralumin made of and used for

Answer 34

Copper and aluminium Aircraft parts

Question 35

What is solder made of and used for

Answer 35

Tin and copper Joining electrical components, copper wires

Question 36

What is brass made of and used for

Answer 36

Copper + zinc Instruments, coins

Question 37

What is bronze made of and used for

Answer 37

Copper and tin Bells, ships, propellers

Question 38

What is corrosion

Answer 38

The reaction of a metal with water and air and other substances in its surroundings

Question 39

What are alloys

Answer 39

The mixture of multiple elements or compounds where at least one is a metal

Question 40

What happens when silver corrodes

Answer 40

Oliver does not react with oxygen and water regularly, but does so in the presence of H2S which is made by bacteria -> a black layer of Ag2S is made

Question 41

What is rusting

Answer 41

A specific type of corrosion that requires oxygen and water to take place Rusting is redox

Question 42

Why is rusting redox

Answer 42

Iron is oxidised (gains oxygens and looses electrons) Oxygen gains electrons in the presence of water to form hydroxide ions

Question 43

How to prevent corrosion

Answer 43

By mitigation

Question 44

What are the 2 mitigation methods

Answer 44

Physical barriers Sacrificial protection

Question 45

Examples of physical barriers

Answer 45

Painting Greasing Electroplating ##footnote Electroplating uses electrolysis, where the cathode is the object and the anode is the metal being coated amd the electrolyte is a solution with the coating material ions

Question 46

Whag is sacrificial protection

Answer 46

A more reactive metal is used to coat the actual metal Since the more reactive one corrodes and looses its electrons more readily, it protects the inner metal

Question 47

Why do you not want to coat a substance with a less reactive metal

Answer 47

While it can help stop corrosion, if there is a scratch in the coating, the inner metal will corrode even quicker than if there was no coating due to the fact that the coating is less reactive than the inner metal which means the inner metal looses electrons more quickly and then corrodes

Question 48

What are ceramic

Answer 48

Hard, non metallic materials They are mostly oxides, so they are fairly un reactive

Question 49

composite materials

Answer 49

2 or more materials combined together

Question 50

What is a lifecycle assessment

Answer 50

An analysis of using and disposing of a manufactured product

Question 51

What does the life cycle assesment check

Answer 51

Sustainability - raw materials, and enrgy needed Environmental impact - raw materials, and energy needed Lifespan - how easy they are to recycle Disposal - how easy the decomposition is

Question 52

Factors that affect recycling

Answer 52

- how easily the waste can be collected and sorted - the amount and type of by products -

Question 53

Rusting practical

Answer 53

Set up three boiling tubes The first tube will contain ANHYDROUS CALCIUM CHLORIDE and the nail -> this chemical absorbs any moisture, keeping the nail dry The nail in this tube WILL NOT rust as rust requires both moisture and oxygen The second tube will have boiled water filled to the top and the nail -> boiled water has NO air in it The nail in this test tube WILL NOT rust as rust The third test tube will have some water and some air and the nail It WILL rust as both water and air present Make sure the nail is made of the same metal, and also the same weight

Question 54

What is an alloy

Answer 54

A mixture of at least one metal with another substance