Titanium is extracted from titanium dioxide using the Hunter process in a two-stage industrial method.
Stage 1 $\quad
\text{TiO}_2 + 2\text{C} + 2\text{Cl}_2 \rightarrow \text{TiCl}_4 + 2\text{CO}$ **Stage 2** $\quad\text{TiCl}_4 + 4\text{Na} \rightarrow \text{Ti} + 4\text{NaCl}$
Suggest one hazard associated with Stage 1.
Suggest why the reaction in Stage 2 is carried out in an atmosphere of argon and not in air.
Titanium chloride (TiCl4\text{TiCl}_4TiCl4) is a liquid at room temperature. Explain why you would not expect a transition metal chloride to be a liquid at room temperature.
During Stage 2, sodium atoms are oxidised to sodium ions. Complete the half-equation for this oxidation.
Na→Na++‾ \text{Na} \rightarrow \text{Na}^{+} + \underline{\qquad\qquad} Na→Na++In Stage 2, 47.5 kg47.5\text{ kg}47.5 kg of titanium chloride was added to 25.0 kg25.0\text{ kg}25.0 kg of sodium. Relative atomic masses (ArA_rAr): Na=23\text{Na} = 23Na=23, Cl=35.5\text{Cl} = 35.5Cl=35.5, Ti=48\text{Ti} = 48Ti=48 Explain why titanium chloride is the limiting reactant. You must show your working.
For a Stage 2 reaction, the percentage yield of titanium was 84.5%84.5\%84.5%. The theoretical maximum mass of titanium produced in this batch was 18.5 kg18.5\text{ kg}18.5 kg. Calculate the actual mass of titanium produced. Give your answer to 3 significant figures.
38 exam-style questions on AQA GCSE Chemistry 3.2 Use of amount of substance in relation to masses of pure substances, covering 3.2.1 Moles (HT only), 3.2.2 Amounts of substances in equations (HT only), 3.2.3 Using moles to balance equations (HT only), 3.2.4 Limiting reactants (HT only), and 3.2.5 Concentration of solutions. Each one has a worked solution and a mark scheme showing where the marks go.