Titanium is a metal used in aircraft and medical implants. It is always found combined with other elements in the Earth's crust and must be extracted from its ore. Explain why titanium cannot be extracted from its ore by heating with carbon, and state the method that is used instead.

Eduqas GCSE Chemistry — 2.3 Metals and their extraction · Explain · 4 marks · View as Markdown

Written & reviewed by James Millett — Biology (Imperial College London), PGCE Science (University of Cambridge).

Titanium is a highly reactive metal found in the ore rutile (titanium dioxide, TiO₂). It is never found as a native metal.

Model answer (4 marks)

Titanium is more reactive than carbon, so carbon cannot displace it from TiO₂.
Carbon is less reactive than titanium, therefore it cannot reduce TiO₂ to Ti.
Titanium is extracted by electrolysis of molten TiCl₄.
Electrolysis requires a large amount of energy, so titanium is expensive to produce.

Examiner tips

  • Use the reactivity‑series argument first; mention carbon’s inability to reduce TiO₂. State the electrolytic method (Kroll process) and note the high energy cost. Keep the answer concise and use the exact terminology.
  • common_mistakes
  • :
  • Claiming that heating with carbon works; ignoring the reactivity series. Forgetting to mention the high energy requirement or the electrolytic method. Using vague terms like "chemical reaction" instead of "reduction".

Mark scheme (4 marks)

  1. Titanium is too reactive / higher in the reactivity series than carbon
  2. Carbon cannot displace / reduce titanium from its ore (because carbon is less reactive than titanium)
  3. Electrolysis is used to extract titanium
  4. Electrolysis requires a large amount of energy / is expensive, making titanium costly to produce

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