A process produces titanium using this reaction.
TiCl4+2Mg→Ti+2MgCl2 \mathrm{TiCl_{4} + 2Mg \rightarrow Ti + 2MgCl_{2}} TiCl4+2Mg→Ti+2MgCl2Titanium is the desired product. Magnesium chloride is a waste product.
| Substance | Relative formula mass (MrM_rMr) |
|---|---|
| Ti\mathrm{Ti}Ti | 47.9 |
| MgCl2\mathrm{MgCl_{2}}MgCl2 | 95.3 |
A chemist states that at least one quarter of the total reactant mass becomes titanium.
Use the equation:
atom economy=Mr of desired productsum of Mr of all products×100 \text{atom economy} = \frac{M_r\text{ of desired product}}{\text{sum of }M_r\text{ of all products}}\times100 atom economy=sum of Mr of all productsMr of desired product×100Calculate the atom economy for producing titanium. Use your answer to evaluate the chemist's statement.
152 exam-style questions on OCR GCSE Chemistry 5.1 Monitoring chemical reactions, covering 5.1.1 The technique of titration, 5.1.2 Theoretical mass, percentage yield and atom economy, 5.1.3 Concentration of a solution in mol/dm3, 5.1.4 Concentration calculations and titration results, 5.1.5 Molar gas volume and volumes of gases in reactions, and 5.1.6 Choosing a reaction pathway. Each one has a worked solution and a mark scheme showing where the marks go.