Ethane reacts with chlorine: C2H6+Cl2→C2H5Cl+HCl\text{C}_2\text{H}_6 + \text{Cl}_2 \rightarrow \text{C}_2\text{H}_5\text{Cl} + \text{HCl}C2H6+Cl2→C2H5Cl+HCl. The bond energies are shown in the table.
| Bond | Bond energy (kJ/mol) |
|---|---|
| C-H | 413 |
| Cl-Cl | 243 |
| C-Cl | 339 |
| H-Cl | 432 |
One C-H bond and one Cl-Cl bond are broken. One C-Cl bond and one H-Cl bond are made.
Calculate the overall energy change, in kJ/mol, and state whether the reaction is exothermic or endothermic.
85 exam-style questions on AQA GCSE Chemistry 5.1 Exothermic and endothermic reactions, covering 5.1.1 Energy transfer during exothermic and endothermic reactions, 5.1.2 Reaction profiles, and 5.1.3 The energy change of reactions. Each one has a worked solution and a mark scheme showing where the marks go.