Topic 4 - Obtaining and using metal ores

Question 1

What is oxidation ?

Answer 1

• The metal gains oxygen
• Happens when something rusts or burns (combusts)
• E.g. magnesium is oxidised to make magnesium oxide

Question 2

What is reduction ?

Answer 2

• Extraction of metal from ores
• The metal loses oxygen when heated with carbon
• E.g. copper oxide is reduced to copper

Question 3

How are metals that are less reactive (Zinc, Iron, Tin, Lead) extracted ?

Answer 3

• Heated with carbon
• This is because carbon is more reactive than the 4 metals so carbon takes the oxygen for itself

Question 4

How are metals that are less reactive (Potassium, Sodium, Calcium, Magnesium & Aluminium) extracted ?

Answer 4

Using electrolysis

Very reactive metals from very stable ores which are difficult to extract the metal from the compound

They have to use electroylsis because they are higher than carbon in the reactivity series

Question 5

What si the word and symbol equation for extracting iron using carbon ?

Answer 5

Iron (lll) oxide + carbon > Iron + carbon dioxide

Question 6

What are the advantages of recycling metals?

Answer 6

• Uses less resources
• Uses less energy - reduces fossil fuel pollution
• Uses less money
• Makes less rubbish - landfill sites are reduced and reduces pollution to the surroundings

Question 7

What are the disadvanatges of recycling metals ?

Answer 7

• Metals need sorting before recycling
• Can be more expensive than recycling as there are costs for collecting and transporting and sorting waste
• The transporting of recycled metal pollutes the air aswell

Question 8

What is an alloy?

Answer 8

• A mixture of two or more metals or a metal + non metal
• Harder than pure metals as they contain different sized atoms whcih prevent them sliding over each other
• alloys can be designed for specific uses

Question 9

What is a smart alloy ?

Answer 9

Have shape memory

E.g. nitionol - alloy of nickel & titanium

It will go back to its original shape when heted

Question 10

What are the exact porperties of aluminium?

Answer 10

• Low density
• corrosion resistant
• Forms hard strong slloysUsed for window rames and aircraft

Question 11

What are the exact properties of gold ?

Answer 11

• Shiny
• extremely easy to shape
• Used for jewellery, tooth fillings and electric circuits

Question 12

What are the exact properties of copper?

Answer 12

• Hard, strong and high meltin gpoint
• Good conductor of electricty
• Use in electrical wires & plumbing

Question 13

Why does corrosio happen ?

Answer 13

The metal is being oxidised

Question 14

What type of metals are more likely to corrode?

Answer 14

Metals which are high in the reactivty series