Chlorine reacts with fluorine to make chlorine trifluoride.
Cl2+3F2→2ClF3 \mathrm{Cl_{2} + 3F_{2} \rightarrow 2ClF_{3}} Cl2+3F2→2ClF3The energy change for the reaction is -315 kJ/mol. Each ClF3\mathrm{ClF_{3}}ClF3 molecule contains three Cl−F\mathrm{Cl{-}F}Cl−F bonds.
| Bond | Cl−Cl\mathrm{Cl{-}Cl}Cl−Cl | F−F\mathrm{F{-}F}F−F |
|---|---|---|
| Bond energy (kJ/mol\mathrm{kJ/mol}kJ/mol) | 243 | 158 |
What is the bond energy of the Cl−F\mathrm{Cl{-}F}Cl−F bond?
67 kJ/mol67\,\mathrm{kJ/mol}67kJ/mol
172 kJ/mol172\,\mathrm{kJ/mol}172kJ/mol
344 kJ/mol344\,\mathrm{kJ/mol}344kJ/mol
516 kJ/mol516\,\mathrm{kJ/mol}516kJ/mol
51 exam-style questions on OCR GCSE Chemistry 3.2 Energetics, covering 3.2.1 Exothermic and endothermic reactions and reaction profiles and 3.2.2 Calculating energy change from bond energies. Each one has a worked solution and a mark scheme showing where the marks go.