In a high-temperature process, sodium combines with chlorine to form sodium chloride. The reaction mixture is maintained at 900 ∘C900\,^\circ\mathrm{C}900∘C under standard pressure.
The equation has been written without state symbols.
2Na+Cl2→2NaCl \mathrm{2Na + Cl_{2} \rightarrow 2NaCl} 2Na+Cl2→2NaCl| Substance | Melting point (∘C^\circ\mathrm{C}∘C) | Boiling point (∘C^\circ\mathrm{C}∘C) |
|---|---|---|
| Sodium | 98 | 883 |
| Chlorine | -101 | -34 |
| Sodium chloride | 801 | 1413 |
Which equation shows the physical state of every substance under these conditions?
2Na(l)+Cl2(g)→2NaCl(l)\mathrm{2Na(l) + Cl_{2}(g) \rightarrow 2NaCl(l)}2Na(l)+Cl2(g)→2NaCl(l)
2Na(g)+Cl2(g)→2NaCl(g)\mathrm{2Na(g) + Cl_{2}(g) \rightarrow 2NaCl(g)}2Na(g)+Cl2(g)→2NaCl(g)
2Na(g)+Cl2(l)→2NaCl(l)\mathrm{2Na(g) + Cl_{2}(l) \rightarrow 2NaCl(l)}2Na(g)+Cl2(l)→2NaCl(l)
2Na(g)+Cl2(g)→2NaCl(l)\mathrm{2Na(g) + Cl_{2}(g) \rightarrow 2NaCl(l)}2Na(g)+Cl2(g)→2NaCl(l)
134 exam-style questions on OCR GCSE Chemistry 3.1 Introducing chemical reactions, covering 3.1.1 Writing formulae and balanced chemical equations, 3.1.2 Formulae of compounds from ions, and state symbols, 3.1.3 Conservation of mass and observed changes in mass, 3.1.4 Half equations and balanced ionic equations, 3.1.5 The mole and the Avogadro constant, and 3.1.6 Stoichiometry, limiting reactants and reacting masses. Each one has a worked solution and a mark scheme showing where the marks go.