Four reactions are being considered for making sodium chloride. Sodium chloride is the desired product in each reaction.
| Equation | Reaction |
|---|---|
| P | 2Na+Cl2→2NaCl\mathrm{2Na + Cl_2 \rightarrow 2NaCl}2Na+Cl2→2NaCl |
| Q | HCl+NaOH→NaCl+H2O\mathrm{HCl + NaOH \rightarrow NaCl + H_2O}HCl+NaOH→NaCl+H2O |
| R | Na2CO3+2HCl→2NaCl+H2O+CO2\mathrm{Na_2CO_3 + 2HCl \rightarrow 2NaCl + H_2O + CO_2}Na2CO3+2HCl→2NaCl+H2O+CO2 |
| S | NaHCO3+HCl→NaCl+H2O+CO2\mathrm{NaHCO_3 + HCl \rightarrow NaCl + H_2O + CO_2}NaHCO3+HCl→NaCl+H2O+CO2 |
| Substance | Relative formula mass (MrM_rMr) |
|---|---|
| NaCl\mathrm{NaCl}NaCl | 58.5 |
| H2O\mathrm{H_2O}H2O | 18.0 |
| CO2\mathrm{CO_2}CO2 | 44.0 |
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}} \times 100 atom economy=sum of Mr of all productsMr of desired product×100Which equation gives an atom economy of 65.4% for making sodium chloride?
Equation R
Equation S
Equation Q
Equation P
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.