Extraction of metals — KCSE Chemistry

KCSE Chemistry · 60 practice questions · 4 syllabus objectives

24 easy19 medium17 hard

What You'll Learn

Key learning outcomes for this topic, aligned to the KNEC KCSE syllabus.

Relate the method of extraction of a metal to its position in the reactivity series

Describe the extraction of iron in the blast furnace including the role of coke, limestone and hot air with equations

Describe the extraction of aluminium by electrolysis of molten aluminium oxide and explain why this method is used

Extraction of metals

Try 3 questions free. Sign up to access all 60 questions with full marking schemes.

easySHORT ANSWER3 marks

Define the process of extracting aluminium from its ore using electrolysis, highlighting the role of molten aluminium oxide. (3 marks)

View Marking Scheme

Part (a) — 3 marks

Electrolysis involves the decomposition of molten aluminium oxide (Al₂O₃) into aluminium and oxygen (1 mk)

Molten aluminium oxide provides ions that are free to move and conduct electricity (1 mk)

The process requires a high temperature to maintain the molten state of aluminium oxide for effective electrolysis (1 mk)

easySHORT ANSWER2 marks

State the role of coke in the blast furnace during the extraction of iron. (2 marks)

View Marking Scheme

Part (a) — 2 marks

Coke acts as a fuel to provide heat for the furnace (1 mk)

Coke reacts with oxygen to produce carbon monoxide, which reduces iron(III) oxide to iron (1 mk)

easySHORT ANSWER4 marks

Name two metals that can be extracted by reduction with carbon and state their positions in the reactivity series. (4 marks)

View Marking Scheme

Part (a) — 2 marks

Iron (1 mk)

Zinc (1 mk)

Part (b) — 2 marks

Iron is below aluminium in the reactivity series (1 mk)

Zinc is also below aluminium but above copper (1 mk)

Name two metals that are extracted using the method of electrolysis and explain why this method is necessary for their extraction. (4 marks)