C1 3 Metals and Their Uses Flashcards
How do we find most metals?
Combined with other chemicals, often with oxygen.
Where are metals found?
In the earth’s crust.
What is a metal ore?
A rock which contains enough of the metal to make it economic to extract the metal.
What has to be done to the ore before the metal is extracted and purified?
Mined and concentrated
What does whether it is worth extracting a particular metal depend on?
- How easy it is to extract it from it’s ore
* How much metal the ore contains
What is a ‘low grade’ rock?
The rock that does not have enough metal to extract.
How may a low grade rock become an economic source of a metal?
A new cheaper method might be discovered or a new more efficient method may be found.
Which metals are found in their native state?
Gold and silver
What does native state mean?
It’s when metals are unreactive and therefore found in the earth as metals themselves.
What is the reactive series?
It shows the reactivity of metals.
How does the reactivity series help with extracting metals?
It shows the best way to extract the metal.
With oxides of metals below carbon, what can we do?
It can be reduced with carbon.
What can a more reactive metal do to a less reactive metal?
It can displace them.
What are the metals combined with oxygen called?
Metal oxides
How is carbon used to extract a metal out of its ore?
The carbon is heated with the metal oxide. The carbon displaces the metal from its ore and combines with the oxygen as carbon dioxide.
Give the equation for carbon displacing a metal from its oxide.
Metal oxide + carbon —> metal + carbon dioxide
What do we call the removal of oxygen from a compound?
Reduction
What are metals more reactive than carbon extracted using?
Electrolysis
Where do we extract iron?
From a blast furnace
What is the exact process if extracting a metal?
The ore is mined Concentrated Metal extracted Purified Object made Object used Object recycled
What is the main source in an iron ore?
Iron oxide
How is iron extracted?
It’s extracted in a blast furnace with coke, limestone, hot air. The limestone removes the impurities, the coke (carbon) displaces the iron from the oxygen (reduction takes place). CO2 is given off and the impurities produce a sold called slag.
What is the iron straight from the blast furnace like? What is it called?
It’s very brittle (mostly carbon) and is called cast iron or pig iron.
What is cast iron used for?
Used to make man-hole covers on roads/engines.
What are the property differences of pure iron and steel?
Pure iron:
Very soft and malleable
Atoms are in even layers therefore if one atom moves the others move.
Steel:
Hard and strong
Carbon disrupts the layers so if one move others don’t.
What can pure iron be alloyed with?
Nickel,chromium or carbon
What is carbon content related to?
Steel strength
What are the two types of carbon steel?
Low carbon steel and high carbon steel
What is used in low carbon steel? What is its property? What is it used for?
Iron and little carbon
Softer
Shaping car bodies
What is used in high carbon steel? What is its property? What is it used for?
Iron and more carbon
Harder
Tool blades
What are stainless steels made of?
Iron and nickel
What are the properties of stainless steel and what is it used for?
It is a high-alloy steel and does not rust. It is used for cutlery.
How is aluminium extracted?
By electrolysis
How does electrolysis work?
Cryolite is used in electrolysis. The aluminium attracts the negative cathodes and the oxygen attracts the positive anodes hence they’re separated.
What is done to aluminium before it is involved in electrolysis?
It is mined, separated from impurities and is melted.
