Titanium is a highly valued transition metal used in aerospace engineering due to its high strength-to-weight ratio and corrosion resistance. In its industrial extraction, titanium dioxide (TiO2TiO_2TiO2) is converted to titanium tetrachloride (TiCl4TiCl_4TiCl4), which is then reduced by molten magnesium at approximately 1000 ∘C1000\text{ }^\circ\text{C}1000 ∘C under an inert argon atmosphere:
TiCl4(g)+2Mg(l)→Ti(s)+2MgCl2(l) TiCl_4(\text{g}) + 2Mg(\text{l}) \rightarrow Ti(\text{s}) + 2MgCl_2(\text{l}) TiCl4(g)+2Mg(l)→Ti(s)+2MgCl2(l)Which of the following statements correctly explains why titanium metal is not extracted by the direct reduction of titanium dioxide (TiO2TiO_2TiO2) with carbon?
Carbon is not a strong enough reducing agent to reduce TiO2TiO_2TiO2, meaning the reduction reaction is thermodynamically impossible at any temperature.
Direct reduction of titanium dioxide with carbon produces titanium carbide (TiCTiCTiC) instead of the pure metal, making the product extremely brittle.
The reaction of titanium dioxide with carbon produces carbon monoxide (COCOCO), which forms a highly toxic, stable gaseous carbonyl complex with titanium that cannot be easily decomposed.
Magnesium is preferred because the magnesium chloride (MgCl2MgCl_2MgCl2) byproduct can be easily electrolysed in an aqueous solution to regenerate the magnesium metal.
Practise Edexcel GCSE Chemistry Obtaining and using metals with exam-style questions for Foundation and Higher tier. 100 questions, matched to the Edexcel GCSE Chemistry (1CH0) specification and written in Paper 1 and Paper 2 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.