C1.3 Metals and their uses

Question 1

What does it mean if an ore is concentrated?

Answer 1

getting rid of the unwanted rocky material

Question 2

Why is gold not found as a compound?

Answer 2

As it is very unreactive

Question 3

What are the 2 ways a metal can be extracted from their ores chemically

Answer 3

electrolysis

reduction

Question 4

When can metals be extracted by their oxides with reduction?

Answer 4

When the metal is less reactive than carbon.

Question 5

What happens during reduction with carbon?

Answer 5

oxygen is removed from the compound

eg iron oxide is reduced in the furnace to make iron

Question 6

How are metals that are more reactive than carbon extracted?

Answer 6

By electrolysis of molten compounds.

Question 7

Why is electrolysis more expensive than reduction with carbon?

Answer 7

it uses a lot of energy.

Question 8

Describe the extraction of copper from copper rich ores

Answer 8

Copper is first extracted from its ores in a furnace- reduction with carbon. The copper is then purified by electrolysis so it conducts electricity better- electrical wiring

Question 9

What 2 ways can copper be extracted from low grade ores?

Answer 9

phytomining

bioleaching

Question 10

Describe phytomining

Answer 10

a way of extracting copper from a low grade ore

uses plants to absorb metal compounds. Plants are then burned to produce ash that contains the metal compounds.

Question 11

Describe bioleaching

Answer 11

A way to extract copper from low grade ores

uses bacteria to produce leachate solutions that contain metal compounds

Question 12

What is a metal ore?

Answer 12

A rock which contains enough metal to make it economic to extract the metal.

Question 13

Describe how copper can be obtained from solutions of copper salts

Answer 13

by electrolysis

Copper is attracted to the negative electrode as it is a positively charged ion. Here, it gains electrons.

Question 14

Describe how ion can be used to obtain copper from copper sulfate

Answer 14

Scrap ion can be used to displace copper from solution as iron is more reactive than copper

copper sulfate + iron — iron sulfate + copper

Question 15

Why can aluminium and titanium not be extracted from their oxides by reduction with carbon?

Answer 15

As they are more reactive than carbon

Question 16

Why are methods to extract aluminium and titanium expensive?

Answer 16

• There are many stages in the process

- Large amounts of energy are needed.

Question 17

Why is metal extraction bad for the environment?

Answer 17

• noise
• scarring of the landscape
• loss of habitats
• deep mine shafts can be dangerous if abandoned

Question 18

What are some benefits of metal extraction?

Answer 18

• useful products can be made
• provides local people with jobs
• brings money into the area- so services such as transport and health are improved.

Question 19

Why is recycling metals important?

Answer 19

• conserves resources- finite amount of each metal on Earth
• reduces landfill
• mining and extracting metals takes a lot of energy- so less fossil fuels are used if you recycle.

Question 20

Iron straight from the blast furnace contains what percentage of iron?

Answer 20

96%

Question 21

What do the impurities of iron straight from the blast furnace make it like?

Answer 21

brittle - so it has limited uses

Question 22

What is iron straight from the blast furnace used for and why?

Answer 22

cast iron because of its strength in compression

Question 23

What is steel a mixture of?

Answer 23

iron and carbon

Question 24

what is a property of low-carbon steel?

Answer 24

easily shaped

Question 25

what is a property of high-carbon steels?

Answer 25

hard

Question 26

what is a property of stainless steel?

Answer 26

resistant to corrosion

Question 27

Why are pure gold, copper, iron and aluminium mixed with small amounts of similar metals?

Answer 27

They are too soft for many uses and so are mixed with small amounts of similar metals to MAKE THEM HARDER for everyday use.

Question 28

Why are alloys harder than pure metals?

Answer 28

Different elements have different sized atoms. This distorts the regular layers, making it difficult for them to slide over each other.

Question 29

What are the elements in the central block of the periodic table know as ?

Answer 29

transition metals

Question 30

Describe the properties of transition metals

Answer 30

- good conductors of heat and electricity | - bent or hammered into shape

Question 31

What are some properties of copper that make it useful for electrical wiring and plumbing?

Answer 31

- good conductor of electricity and heat - can be bent but is hard enough to be used to make pipes or tanks - does not react with water

Question 32

Why are aluminium and titanium useful metals?

Answer 32

low density resistance to corrosion

Question 33

What are some disadvantages of using metals as structural materials?

Answer 33

- Some corrode when exposed to air and water so need to be painted ----- if a metal corrodes, it loses its strength and hardness - Metal fatigue- leads to metals breaking- dangerous

Question 34

Why is titanium more expensive than iron?

Answer 34

there are more stages in the process more energy/materials are needed to extract it titanium is more reactive than titanium so cannot be extracted using carbon

Question 35

Why is air removed and replaced with argon in the reaction between titanium chloride and magnesium metal to produce titanium?

Answer 35

because oxygen in the air would react with magnesium and produce magnesium oxide whereas argon is unreactive so does not react

Question 36

Why is copper extracted from ores containing a low percentage of coper compounds?

Answer 36

copper ores are running out and are harder to find copper metal is in demand now economical to extract copper from low grade ores

Question 37

Why is it difficult to dispose waste rock?

Answer 37

takes up a lot of space

Question 38

What is used in phytomining to remove copper compounds from the land?

Answer 38

plants

Question 39

what are some advantages and disadvantages of recycling materials from a ball point pen?

Answer 39

conserves resources reduces use of landfill less use of energy less carbon dioxide produced made from different materials diffuculty and cost of separating the different materials

Question 40

Why are alloys used in a ball point pen?

Answer 40

so it is hard and strong so it is resistant to corrosion so it does not rust

Question 41

Why does extracting copper from the land using traditional methods have a major environmental impact?

Answer 41

- produces large amounts of solid waste - causes atmospheric pollution from carbon dioxide + sulphur dioxide - more lorries to transport bulky material

Question 42

Why is it economical to use scrap iron to get copper?

Answer 42

iron is cheap

Question 43

Why can iron be used to get copper from copper sulfate solution?

Answer 43

iron displaces copper from solutions of its salts because iron is more reactive than copper

Question 44

What are some advantages of phytomining rather than using traditional methods to extract metal?

Answer 44

- carbon neutral - as plants remove carbon dioxide from the atmosphere as they grow - less expensive as less energy is needed to extract the small amounts of copper

Question 45

Suggest a disadvantage of phytomining rather than traditional methods to extract metals

Answer 45

it is not a continuous process as it takes a long time for plants to grow

Question 46

What is smelting?

Answer 46

When copper is extracted from copper rich ores by heating the ores in a furnace

Question 47

Suggest why an ore needs to be separated before the metal is extracted

Answer 47

as the ore is not pure so the other compounds need to be removed

Question 48

Describe how cast iron is converted into steel

Answer 48

in the furnace, oxygen reacts with the carbon in the iron which reduces the percentage of carbon in the mixture as carbon dioxide is produced

Question 49

what is the property of aluminium which makes it more suitable for overhead cables than copper?

Answer 49

aluminium is low density

Question 50

How can you tell that copper is a transition metal and aluminium is not a transition metal for their position in the periodic table?

Answer 50

copper is in the central block in the periodic table whereas aluminium is in group 3

Question 51

What is an alloy?

Answer 51

a mixture of metals

Question 52

explain why the need for copper will cause a problem in the future

Answer 52

as we are running out of copper ores

Question 53

suggest ways society could overcome the problem that copper ores are running out

Answer 53

use low grade copper ores- from phytomining/bioleaching reuse/recycle copper use other materials instead

Question 54

what is meant by a smart alloy?

Answer 54

an alloy that can return to its original shape when heated

Question 55

Name the element that is removed from ores when they are reduced

Answer 55

oxygen

Question 56

how is iron ore reduced in a blast furnace to make iron?

Answer 56

the iron ore is heated carbon in the air reacts with oxygen in the ore - displaces the oxygen

Question 57

Explain why copper from areas that contain a very low percentage of copper compound is not extracted by smelting

Answer 57

land contains very little copper uneconomical

Question 58

What happens to copper ions during electrolysis?

Answer 58

copper ions are attracted to the negative electrode where they are reduced (gain 2 electrons) copper metal is formed