Making resources

Question 1

What is corrosion

Answer 1

When a material reacts with substances in the environment and eventually wears away

Question 2

How can corrosion be prevented

Answer 2

Physical barriers
Sacrificial protection

Question 3

What is rusting and how does it occur

Answer 3

Example of corrosion

Caused by iron reacting with oxygen and water from the environment

Question 4

Physical barriers for rusting

Answer 4

Grease, paint or thin layer of another metal

Question 5

What is electroplating and explain process

Answer 5

Thin layer of metal on material to stop rusting

Aluminium reacts with oxygen to make a thin layer of aluminium oxide around the metal that acts as a physical barrier which protects the rest of the metal from corrosion

Question 6

What is sacrificial protection

Answer 6

Adding a more reactive metal to the surface of a material

Question 7

What is an example of sacrificial protection

Answer 7

Iron is galvanised with zinc

Zinc will react with oxygen and water in the place of iron

Question 8

What are two alloys of copper

Answer 8

Brass
Bronze

Question 9

What are gold alloys in jewellery made from

Answer 9

Gold with copper, zinc and silver

Question 10

What are steel alloys made from

Answer 10

Iron
Carbon
Other metals

Question 11

What is a property of aluminium alloys

Answer 11

Generally have low densities

Question 12

What is the main difference between soda-lime and borosilicate glass

Answer 12

Borosilicate glass has a much higher melting point

Question 13

Give two examples of clay ceramics

Answer 13

Pottery
Brick

Question 14

How to manufacture clay ceramics

Answer 14

Shape wet clay then heat in a furnace

Question 15

Properties of clay ceramics

Answer 15

Hard
Brittle
Easy to shape before manufacture
Resistant to corrosion

Question 16

What do the properties of polymers depend on

Answer 16

Monomers that make them up
Conditions under which they are made

Question 17

How is low density poly(ethene) formed

Answer 17

When addition polymerisation reaction of ethene is carried out under high pressure and in the presence of a small amount of oxygen

Question 18

Why does the low density poly(ethene) have a low density

Answer 18

The branched polymer chains cannot pack together

Question 19

How is high density poly(ethene) formed

Answer 19

When the addition polymerisation reaction of ethene is carried out using a catalyst at 50 degrees

Question 20

Why does high density poly(ethene) have a high density

Answer 20

Polymer chains are straight and can pack tightly together

Question 21

Describe thermosoftening polymers

Answer 21

Do not have links between different chains

Soften when heated

Question 22

Describe thermosetting polymers

Answer 22

Chains fixed together by strong covalent bonds - cross-linking

Do not melt when heated

Question 23

What are composites

Answer 23

Made from main material (matrix) with fragments or fibres of other materials (reinforcement) added

Question 24

Two examples of composites

Answer 24

Plywood
Reinforced concrete

Question 25

What process produces ammonia

Answer 25

The haber process

Question 26

What is ammonia used for

Answer 26

Fertilisers

Question 27

What is the word and symbol equation for the haber process

Answer 27

N2+ 3H2 ——> 2NH3

Nitrogen + hydrogen to ammonia

Question 28

What type of reaction is the haber process

Answer 28

Reversible reaction

Question 29

What is the method for the haber process

Answer 29

Hydrogen from natural gas and nitrogen from the air are pumped in

The nitrogen/hydrogen mixture is compressed to a pressure of 200 atm and heated to 450 degrees

Passed through reaction vessel containing iron catalyst

The mixture of gases emerging from the reactor is cooled in the cooling chamber; ammonia is liquified and separated

Unreacted nitrogen and hydrogen are returned to the reaction vessel via the compressor

Question 30

What are the conditions used for the haber process and why

Answer 30

Iron catalyst
Temps around 450 degrees
Pressure of 200 atmospheres

Compromise to balance yield, cost, rate

Question 31

Why is the temp for the haber process 450 and not any lower

Answer 31

Forward reaction is exothermic so even though lowering the temp would increase yield of ammonia it would decrease the rate of reaction

Question 32

Why is pressure 200 atmospheres and not any higher

Answer 32

There are fewer gas molecules on the product side so even though when there is a higher pressure there would be a higher yield and rate, it is too expensive

Question 33

Why is an iron catalyst used for the haber process

Answer 33

Does not increase yield but increases rate of reaction

Question 34

What are in NPK fertilisers

Answer 34

Nitrogen
Phosphorus
Potassium

Question 35

Explain how NPK fertilisers are formulations

Answer 35

Some substances that go into NPK fertilisers can be mined straight from the ground
Others like phosphate rocks need to be processed first

Question 36

How can phosphate rock be processed

Answer 36

React with different acids to make different products which can either be used as fertilisers on their own or added to an NPK fertiliser

Question 37

Where can the compounds found in fertilisers be produced

Answer 37

In a laboratory or industrially

Question 38

Explain the quantities, process, apparatus and speed used in a laboratory when producing compounds for fertilisers

Answer 38

Small quantities produced

Done in batches

Glass apparatus

Slow speed

Question 39

Explain the quantities, process, apparatus and speed used industrally when producing compounds for fertilisers

Answer 39

Large quantities produced

Continuous process

Stainless steel apparatus

Fast speed