Metals

Question 1

3 ways of extracting metals

Answer 1

1. Electrolysis (reactive metals)
2. Blast furnace (medium reactive)
3. Purify (unreactive)

Question 2

Name of iron(III) oxide ore found in nature

Answer 2

Haematite

Question 3

Steps to extract iron

Answer 3

1. Coke + oxygen in air
   C + O2 –> CO2
2. Carbon dioxide + coke
   CO2 + C –> 2CO
3. Carbon monoxide + iron ore (redox reaction)
   3CO + Fe2O3 –> 2Fe + 3CO2
4. Decomposition of quicklime by heat
   CaCO3 –> CaO + CO2
5. Removal of the acidic impurity
   CaO + SiO2 –> CaSiO3

Question 4

Characteristics of high carbon, mild steel, chromium steel, stainless steel

Answer 4

Brittle, strong
Malleable strong
Extremely hard
Prevents rusting

Question 5

What are the conditions essential for rusting to take place?

Answer 5

Water + oxygen

Question 6

What is sacrificial protection?

Answer 6

Reactive metal rusts to protect less reactive metal

Question 7

What is surface protection?

Answer 7

Physical protection against oxygen & moisture in air that will cause rust

Question 8

Name of aluminium ore

Answer 8

Bauxite