9.3 Extraction of Metals

Question 1

What are the 3 ways in which metals are extracted from their ores?

Answer 1

• Electrolysis
• Displacement
• Blast Furnace

Question 2

How is iron extracted from hematite?

Answer 2

Blast Furnace

Question 3

State what happens in the bottom of the blast furnace during extraction of iron

Answer 3

Coke burns in hot air forming CO₂

carbon + oxygen → carbon dioxide

Question 4

State the 3 symbol equations for extraction of iron

Answer 4

Fe₂O₃ (s) + 3CO (g) → 2Fe (I) + 3CO₂ (g)

CaCO₃ (s) → CaO (s) + CO₂ (g)

CaO (s) + SiO₂ (s) → CaSiO₃ (l)

Question 5

Which ore contains iron?

Answer 5

Hematite

Question 6

Which ore contains aluminium?

Answer 6

Bauxite

Question 7

How is aluminium extracted from bauxite?

Answer 7

Electrolysis

Question 8

What is added to aluminium oxide during this electrolysis?

Answer 8

Molten Cryolite

Question 9

What does molten cryolite do?

Answer 9

Reduce the melting point without interfering in the reaction

Question 10

Equation at the cathode for electrolysis of aluminium oxide?

Answer 10

Al³⁺ + 3e⁻ → Al

Question 11

Equation at the anode for electrolysis of aluminium oxide?

Answer 11

2O²⁻ → O₂ + 4e⁻

Question 12

What is the overall reaction for the electrolysis of aluminium oxide?

Answer 12

2Al₂O₃ → 4Al + 3O₂