Question

Aluminum is extracted from purified bauxite by electrolysis but iron is extracted from haematite by reduction with coke. Why is iron not extracted by electrolysis?

• A. (a) Haematite needs to be purified but bauxite does not.
• B. (b) Iron is less reactive than Aluminum.
• C. (c) Reduction with coke is cheaper than electrolysis.
• D. (d) Reduction with coke gives a pure product than electrolysis.

Answer 1

The correct option is B

(b) Iron is less reactive than Aluminum.

Extraction of metal from ore:

Reduction of metal oxides: Metal oxides present in the middle of the reactivity series Zinc, Iron, Tin and Lead are less reactive than Carbon, so reduced to free metals by using Carbon.

By electrolysis: Most reactive metal oxides like Aluminum, sodium, Potassium, Magnesium and calcium can not be prepared by reduction with carbon, they are extracted by electrolytic reduction.

So depending on the metal's position in the reactivity series the extraction method used.