Unit 2 Topic 7 Materials

Question 1

Why nanoparticles have different properties to larger particles?

Answer 1

This is because they have a higher surface area to volume ratio

Question 2

Give use for gold nanoparticles?

Answer 2

Catalysts to convert carbon monoxide in to carbon dioxide

Question 3

Give 3 properties of silver nanoparticles?

Answer 3

Antibacterial
Anti fungal
Anti viral

Question 4

Give 2 uses of carbon nano tubes?

Answer 4

• Mini electronic devices

- Smaller faster computers

Question 5

How can nanoparticles be used as coating?

Answer 5

Thin layers of scratch resistant polymers can be used to protect lenses

Question 6

Give 2 ways of extracting metals from ore?

Answer 6

Electrolysis

Chemical reduction

Question 7

What is electrolysis?

Answer 7

The breaking down of compounds in to simpler substances using electric current

Question 8

What is an electrolyte?

Answer 8

An ionic compound that’s been melted or dissolved

Question 9

What is a cathode?

Answer 9

The electrode attached to the negative pole

Question 10

What is an anode?

Answer 10

The electrode attached to the positive pole

Question 11

What is an electrode?

Answer 11

Metal or Graphite rods placed in to liquid and connected to a supply of electricity

Question 12

Which electrode are anions attracted to?

Answer 12

Anode

Question 13

Which electrode are cations attracted to?

Answer 13

Cathode

Question 14

Give an observation of pure lead produced at the cathode after electrolysis?

Answer 14

Silvery bead

Question 15

Give a observation of pure bromine produced at anode?

Answer 15

Brown gas

Question 16

Give an observation of pure lithium that forms at cathode?

Answer 16

Grey liquid

Question 17

Give an observation of pure chlorine produced at anode?

Answer 17

Pale green gas

Question 18

How is Aluminium manufactured?

Answer 18

Electrolysis of Aluminium ore (Bauxite)

Question 19

What is Bauxite?

Answer 19

Aluminium ore, which is Aluminium Oxide

Question 20

What temperature is electrolysis of Aluminium carried out at?

Answer 20

955°C

Question 21

Give 2 purposes of cryolite?

Answer 21

Lowers melting point of bauxite

Allows mixture of molten liquids to conduct electricity

Question 22

Give 2 reasons to recycle aluminium?

Answer 22

Most cost effective metal to recycle

Recycling aluminium requires only 5% of energy required to manufacture aluminium

Question 23

How is Iron extracted from its ore?

Answer 23

Blast Furnace (Chemical Reduction)

Question 24

What is Iron ore also known as?

Answer 24

Haematite

Question 25

Give the 3 stages of the extraction of Iron from its ore?

Answer 25

- 1. Formation of reducing agent ( Carbon Monoxide) - 2. Reduction of iron oxide to iron - 3. Removal of impurity

Question 26

Give equations of all the reactions in extraction of iron?

Answer 26

Stage 1: - C + O2 ---> CO2 - CO2 + C ---> CO Stage 2: - Fe2O3 + 3CO ---> 2 Fe + 3CO2 Stage 3: - CaCO3 ---> CaO + CO2 - CaO + SiO2 ---> CaSiO3

Question 27

What 3 reactants are used in extraction of iron?

Answer 27

Iron ore ( Haematite) Limestone Coke ( Carbon)

Question 28

Why is Limestone used in extraction of iron?

Answer 28

It thermally decomposes to Calcium Oxide, which then reacts with the sand impurity in iron ore, Silicon Dioxide. This forms Calcium Silicate, which is also known as slag, which then floats on top of the pure iron as it is less dense

Question 29

What is Calcium silicate also known as?

Answer 29

Slag

Question 30

Give 2 uses of slag?

Answer 30

Build roads | Build foundations for buildings

Question 31

Give 2 ways in which production of iron helps the economy?

Answer 31

Provides jobs | Provides exports

Question 32

Give 3 environmental problems with production of iron?

Answer 32

Air pollution Noise pollution Unsightly slag heaps

Question 33

Give 1 disadvantage and 2 advantages of recycling the raw materials used in iron production?

Answer 33

- Sorting recycled materials is expensive - Less energy used - Saves resources

Question 34

Give 2 disadvantages and 1 advantage of disposing or incinerating materials?

Answer 34

- Toxic / polluting products released in to atmosphere - Landfill wastes land - Heat energy from incineration can be harnessed to generate electricity

Question 35

Give 2 disadvantages and 1 advantage of producing new materials?

Answer 35

- More mining and drilling for materials - More pollution - More jobs created

Question 36

What is nanotechnology?

Answer 36

The study of atoms and molecules