Titanium is extracted from its main ore, rutile (TiO2\text{TiO}_2TiO2), in a three-stage process.
Stage 1: Rutile is heated with chlorine and coke (carbon) at a temperature of about 900 ∘C900\ ^\circ\text{C}900 ∘C.
TiO2+2Cl2+2C→TiCl4+2CO \text{TiO}_2 + 2\text{Cl}_2 + 2\text{C} \rightarrow \text{TiCl}_4 + 2\text{CO} TiO2+2Cl2+2C→TiCl4+2COStage 2: Titanium tetrachloride (TiCl4\text{TiCl}_4TiCl4) is then reacted with liquid sodium at a temperature of about 800 ∘C800\ ^\circ\text{C}800 ∘C in an inert atmosphere of argon.
TiCl4+4Na→Ti+4NaCl \text{TiCl}_4 + 4\text{Na} \rightarrow \text{Ti} + 4\text{NaCl} TiCl4+4Na→Ti+4NaClDuring the reaction, the temperature rises significantly due to the exothermic nature of the process.
Stage 3: The sodium chloride is removed by vacuum distillation from the mixture formed in stage 2, leaving behind pure titanium.
In stage 1, is the chlorine oxidised or reduced? Give a reason for your answer.
What does the reaction in stage 2 indicate about the reactivity of sodium compared to the reactivity of titanium? Explain your answer.
In stage 3, suggest why distillation can be used to separate sodium chloride from titanium.
Titanium has these properties:
Complete the table below to suggest an important property of titanium for each use. Choose from the four properties listed above. You must choose a different property for each use.
| Use | Property |
|---|---|
| joint replacements and dental implants | |
| heat exchangers in chemical desalination plants | |
| structural components of high-speed aircraft |
