3 Metals And Their Uses Flashcards
What two things are considered when working out whether or not to extract a metal? 2
- how easy it is to extract it from its ore
- how much metal the ore contains
Give examples of metals that are found combined with oxygen?4
Copper
Lead
Zinc
Iron
When a more reactive metal is combined with a less reactive metal what will it do to it?
Displace it
How are gold and silver found?
As the elements themselves (
If a metal is combined with oxygen what has to be done before you can use it?
It has to be chemically separated before it can be used
If there is enough in a rock to make it economic to extract it what do we call the rock?
A metal ore
Why is gold found as a metal rather than combined with elements in compounds?
They are so unreactive
What is meant by reduction?
The removal of oxygen from a compound
How are metals more reactive than carbon extracted?
By electrolysis
Why is platinum being so unreactive useful with rings?
Being so unreactive means that the ring will last longer as it will be unaffected by external factors
How is iron ore reduced?
By using carbon in a blast furnace
Why is iron from a blast furnace not very useful?
Pre iron is too soft for it to be very useful
What is an allow?
A metal that is mixed with other elements
What is steel an alloy of?
Iron
What are the three main types of steel and their main property?6
- low carbon steels which are easily shaped
- high carbon steels which are very hard
- stainless steels which are resistant to corrosion
How is iron changed to make it useful?
Carefully controlled quantities of carbon and other elements are added to iron to make alloys of steel with different properties
What is cast iron?
When iron from the blast furnace, poured into moulds and left to solidify is called cast iron
How does cast iron differ from pure iron?4
- cast iron contains impurities
- making it harder and less reactive than pure iron
- pure iron combined oxygen will rust wheras cast iron won’t
Why do surgical instruments made from steel contain chromium and nickel?3
To make it harder and stronger as well as lasting longer
Why are aluminium and titanium do useful?
They are resistant to corrosion
Where do metals come from?
- metals are found in the earths crust
What are stainless steels?
Chromium-Nickel steels
What are some common uses of aluminium? 6
- drink cans
- cooking foil
- saucepans
- aeroplanes
- high voltage cables
- bicycles
Name six characteristics of aluminium?
- light
- relatively low density
- excellent conductor of energy and electricity
- malleable
- doesn’t corrode easily
- relatively reactive
How is aluminium extracted?4
By electrolysis
An electric current is passed through molten aluminium oxide at high temperatures to break it down
Why do we use titanium for parts of jet engines?
Because it keeps its strength even at high temperatures
Why is titanium used in nuclear reactors? 3
It can stand up to high temperatures and it’s tough oxide layer means that it’s resistant to corrosion
Why is titanium used for replacement hip joints l?3
Low density (light)
Strength
Resistance to corrosion
properties of titanium?4
Light
Strong
Resistant to corrosion
High melting point
Why is it expensive to extract aluminium and titanium?2
Large amounts of energy is needed and there are lots of stages
What methods can be used to obtain copper from low grade ores?2
- bacteria are used in bioleachond
- plants in phytomining
How is copper purified?
Electrolysis
Why are metals always deposited at the negative electrode?
Because they are always positively charged
What electrode are metals always deposited at?
Negative electrode
What is smelting?
When copper is extracted from its ore by heating
What chemical do we use to treat copper ore in order to form copper sulfate?
Sulfuric acid
Why is gold made into an allow in jewellery?
To make it last longer and harder
Why would copper be useful to a plumber?
- it carries water
- it conducts electricity
Name three properties of the transition metals?
- strong
- but can be bent or hammered into useful shapes
- good conductors of electricity and energy
When pure copper is alloyed with tin what does it make?
Bronze
When pure copper is alloyed with zinc what does it make?
Brass
How can plants help to exploit low grade metal ores?
The metals can be recovered by processing the ash and burning the plants
Why should we recycle metals?3
Because it saves energy
And out limited metal ores and fossil fuels
The pollution from extracting metals is also reduce d
What is the problem with smelting for copper?
It is impure, it needs to be by electrolysis
Describe phytomining?
This involves growing plans in soil that contains copper
The copper absorbs in the leaves
The plants can be burned in a furnace
The copper can be collected from the ash left in the furnace
Why is titanium more e pensive than iron?
Many stages needed to extract titanium
More energy and materials are needed to extract titanium
Why is copper extracted from ores containing a low percentage of copper compounds?
Copper is running out There are no amounts of high grade copper ores left Copper is expensive It is now economical to extract from Low grade ores
Why is the extraction of pure copper expensive?
Large amounts of fuels used
Extraction had many steps
Large amounts of material have to be mined
In electrolysis what electrode do the copper ions move towards?
Negative electrode
Because copper joke are positively charged
What is used in phytomining to remove copper compounds from land?
Plants
Name the type of reaction that releases energy from a fuel?
Exothermic
Why use alloys?
Hard strong
Resistant to corrosion
Advantages of biodiesel?
Produced less carbon dioxide and no sulphur dioxide Produced less particulates Renewable Less acid rain Conserved resources Carbon neutral
Disadvantages of biodiesel?
Produced more nitrogen oxides Deforestation for land Land could have been sued for food Crops are unreliable Destruction of habitats
Why would smelting not be used?
Little copper so is uneconomical
describe what happens to copper ions during electrolysis?
Copper ions are attracted to the negative electrode
Where they are reduced
Why is argon used in extraction?
It is very unreactive
Why is titanium more expensive than iron?
More stages in its manufacture
Larger amounts of energy needed
Argon had to be produced as titanium is reactive
Why extract iron instead of aluminium?
Iron used less energy for extraction More used More demand Stronger Cheaper
Suggest two reasons why aluminium drink cans should be recycled?
Saved resources Landi Saves energy Less carbon dioxide Less quarrying
What type of metals are extracted by electrolysis?
Metals that are more reactive than carbon have to be extracted by electrolysis
Properties and uses of stainless steel?
Resistant to corrosion
Cutlery
Containers for corrosive substances
Properties and uses of high carbon steel?
Very hard and inflexible
Blades for cutting tools
Bridges
Properties and uses of low carbon steel?
Easily shaped
Car bodies
Why is pure iron softer than cast iron?
Easier for layers in pure iron to slide over eachother
Same size atoms
What are most metals found as?
Compounds that require chemical reactions to extract the metal
How can copper be extracted from copper rich ores?
Smelting
Then purified by electrolysis
How can copper be obtained from solutions of copper salts?
Electrolysis
Or
Displacement using scrap iron
Describe phytomining?
Plants absorb dissolved metal ions in the soul through their roots
Plants burned metals extracted from ash
Then eg Copper ions can be leached (dissolved) from the ash by adding sulphuric acid
Making a solution of copper sulphate
Electrolysis can purify this
Why should we recycle metal?
Extracting them used limited resources and is expensive in terms of energy
Also effects the environment
What makes iron brittle?
It contains impurities
What are steels?
Mixtures of iron with carbon
Properities of copper?
Good conductor
Can be bent but is hard enough to be used to make pipes or tanks
Does not react with water
What is copper useful for?
Electrical wiring
Plumbing
Why are both titanium and aluminium useful metals?
Low density
Resistant to corrosion
What is cast iron used to make?
Wood burning stoves
Engines
Why is titanium used for aircrafts and racing bikes?
Strength
Low density
Why is titanium used for jet engines and nuclear reactors?
Can withstand high temperatures
Resistant to corrosion
How is bronze made?
Mixing copper with ton
How is brass made?
Mixing copper with zinc
Copper properties?
Tough
Resistant to corrosion
Used in ship propellers
Properties of brass?
Very hard but worked le
Can be hammered into sheets and intricate shaped
Used to make musical instruments
What is copper used for?
Pipes that carry water (dosent react with water)
Wired that contact electricity
Why recycle metal?
Reduces the need to mine the metal ore
Conserved resources
Saves energy
Used of steel?
Bridges
Skyscrapers
Concrete bridges (reinforced with steel rods)
Describe bio leaching?
Bacteria grow on the ore
Produce a solution as a byproduct of this
Solution can then be purified using electrolysis or displacement using scrap iron
How do you extract copper from its ore?
Smelting
React with sulphuric acid
Extracting using carbon is an example of what type of reaction?
Reduction
