P2 - Using Resources

Question 1

Define ceramics

Answer 1

Non-metal solids with high melting points. They aren’t made from carbon-based compounds. They are made from materials such as clay or glass

Question 2

What is the difference between soda-like glass and borosilicate glass and what are they both made of?

Answer 2

Soda-lime has a lower melting point.
Both made of a mixture of sand with other substances:
Soda-lime with limestone and sodium carbonate
Borosilicate with boron trioxide

Question 3

Define composites

Answer 3

Made of one material embedded in another. Fibres/fragments surrounded by matrix acting as binder.

Question 4

What are the four types of composites and their properties?

Answer 4

• Fibreglass - glass in polymer- low density and very strong
• Carbon fibre - polymer matrix, chain of carbons or carbon nanotubes - very strong and light
• Concrete - aggregate(sand and gravel) in cement - very strong
• Wood - cellulose fibres in polymer - natural

Question 5

What causes different densities in poly(ethene)?

Answer 5

Low density - moderate temp under high pressure

High density - low temp under low pressure with different catalyst

Question 6

What is the difference between thermosoftening and thermosetting polymers?

Answer 6

Thermosoftening - individual polymer chains joined by weak forces, can be melted
Thermosetting - contain monomers and cross links between chains, don’t soften, very hard

Question 7

What are the properties of each of the materials?

Answer 7

Ceramics - insulators, brittle
Polymers - insulators, flexible, easily moulded
Composites - strength depends on matrix
Metals - malleable, good conductors, ductile, stiff , shiny

Question 8

Define an alloy

Answer 8

Made by adding another element to a metal to make it stronger.

Question 9

Which elements corrode easily?

Answer 9

Iron and steel

Question 10

What is needed for iron to rust?

Answer 10

Both Air and water

Question 11

What are the two main ways to prevent rusting?

Answer 11

Paint it
Electroplating (electrolysis to coat with different metal)
Oiling/greasing
Galvanised in zinc (sacrificial protection)

Question 12

Define finite resources

Answer 12

Means non-renewable so it will eventually run out

Question 13

Advantages and disadvantages of extracting finite resources

Answer 13

Advantages - useful products made, creates jobs, brings money
Disadvantages - uses lots of energy, scars landscape, produces waste, destroys habitats

Question 14

Define bioleaching

Answer 14

Bacteria are used to convert copper ore into soluble copper compounds by separating copper from ore. The leachate (solution produced) contains copper ions which are extracted by electrolysis or displacement reaction.

Question 15

Define phytomining

Answer 15

Growing plants in soil that contains copper. Copper builds up in leaves and when harvested are dried and burned. The ash contains soluble copper compounds which are extracted by electrolysis or displacement reaction.

Question 16

How is glass recycled?

Answer 16

It is crushed and melted.

Question 17

What are the four stages of the Life Cycle Assessment?

Answer 17

1. Raw materials - extraction damages environment and uses energy
2. Manufacture and packaging - causes pollution, uses energy, some waste turned into useful chemicals
3. Using product - Can damage environment (depends on use), the length of use (longer life means less waste)
4. Product disposal - landfills pollute, energy used in transportation, may be incinerated causing air pollution.

Question 18

Define potable water

Answer 18

Water that’s been treated so is safe to drink.

Question 19

What are the different ways of making potable water?

Answer 19

Filtration + Sterilisation - wire mesh removes twigs, sand and gravel beds filter any solid particles; water sterilised by chlorine to kill harmful bacteria or microbes.

Distillation - test for correct pH (if too high/low use titration to neutralise); test for sodium chloride; heat water to form steam, condenses in condenser to form water.

Question 20

Define reverse osmosis

Answer 20

Salty water passed through membrane that only allows water particles to pass - separates water from salt

Question 21

What is the disadvantage of distillation and reverse osmosis to produce potable water?

Answer 21

It uses a lot of energy

Question 22

Describe the stages of waste water treatment

Answer 22

1. Screened - to remove large bits
2. Sedimentation - heavy solids sink to produce sludge while light floats on top called effluent
3. Aerobic digestion - air pumped through effluent to get bacteria to break down organic matter and microbes
4. Anaerobic digestion - sludge broken down releases methane as energy source
5. If contains toxins then add chemicals like UV radiation

Question 23

Define the Haber Process

Answer 23

Makes ammonia from hydrogen and nitrogen by being passed over a catalyst. This is a reversible reaction. Ammonia used in fertilisers.

Question 24

What do fertilisers do?

Answer 24

Replace missing elements or provide more of them which increases crop yield.

Question 25

What does NPK Fertilisers stand for?

Answer 25

N - nitrogen
P - phosphorus
K - potassium