Extracting metals from their ores
3 marks · NormalThe diagram below shows a section of the reactivity series for four metals, with their possible methods of extraction:
| Metal | Part of Reactivity Series (Rank: 1 = most reactive) | Method used to extract from ore |
|---|---|---|
| Potassium | 1 | |
| Magnesium | 3 | |
| Zinc | 6 | |
| Silver | 10 |
Metals above carbon in the reactivity series are usually extracted by electrolysis, metals below carbon but above hydrogen can be extracted by reduction with carbon, and very unreactive metals may be found as the element.
Complete the table by writing the likely method of extraction for each metal. Choose from: electrolysis, reduction with carbon, or found native.
Write your answers clearly in your answer booklet in the same order as the metals listed.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
Potassium: electrolysis; Magnesium: electrolysis; Zinc: reduction with carbon; Silver: found native
(a) Potassium: electrolysis
(b) Magnesium: electrolysis
(c) Zinc: reduction with carbon
(d) Silver: found native
Also accept: Silver: found as element; Silver: found uncombined; Zinc: by heating with carbon
Common mistakes: Mixing up methods for metals above or below carbon; Stating 'electrolysis' for zinc
Show mark scheme and worked solution
Marking points
M1 · 1 mark · Any correct assignment of method for metals above carbon (i.e., potassium or magnesium: electrolysis)
M2 · 1 mark · Any correct assignment of method for a metal below carbon but above hydrogen (zinc: reduction with carbon)
A1 · 1 mark · Any correct assignment for an unreactive metal (silver: found native)
Worked solution
Potassium is above carbon in the reactivity series, so it must be extracted by electrolysis.
Magnesium is also above carbon, so its extraction is also by electrolysis.
Zinc is below carbon but above hydrogen, so it can be extracted by reduction with carbon.
Silver is very unreactive and is often found native (as the element) in the Earth's crust.
| Metal | Rank | Method of Extraction |
|---|---|---|
| Potassium | 1 | Electrolysis |
| Magnesium | 3 | Electrolysis |
| Zinc | 6 | Reduction with carbon |
| Silver | 10 | Found native |