Titanium is extracted from titanium(IV) oxide (TiO2\text{TiO}_2TiO2) in a multi-step process. In the final stage, titanium(IV) chloride is reduced using magnesium at a temperature of about 1000 K:
TiCl4(g)+2Mg(l)→Ti(s)+2MgCl2(l) \text{TiCl}_4(\text{g}) + 2\text{Mg}(\text{l}) \rightarrow \text{Ti}(\text{s}) + 2\text{MgCl}_2(\text{l}) TiCl4(g)+2Mg(l)→Ti(s)+2MgCl2(l)Which statement correctly explains why this specific process is used, or describes a key chemical detail of the reaction?
The reduction of TiCl4\text{TiCl}_4TiCl4 with magnesium is run as a continuous process to keep energy and labor costs low.
Magnesium acts as an oxidising agent in this reaction, gaining electrons to form Mg2+\text{Mg}^{2+}Mg2+ ions.
Direct reduction of TiO2\text{TiO}_2TiO2 with carbon is avoided because titanium carbide (TiC\text{TiC}TiC) is formed, which makes the metal extremely brittle.
The reaction is conducted under a nitrogen atmosphere to prevent the reactants from being oxidised by air.
110 exam-style questions on Edexcel GCSE Chemistry 5.1 Obtaining and using metals, covering 5.1.1 The reactivity series of metals, 5.1.2 Displacement reactions as redox reactions, 5.1.3 Extracting metals from ores by reduction, 5.1.4 Biological methods of metal extraction, 5.1.5 Resistance to oxidation and recycling metals, and 5.1.6 Life cycle assessment. Each one has a worked solution and a mark scheme showing where the marks go.