Methane gas burns in a gas cooker. The gas does not start to burn until a spark from the igniter is used.
The table gives information about the reaction profile for the combustion of methane.
| Point on the reaction profile | Energy / kJ |
|---|---|
| reactants | 1000 |
| highest point of the curve | 1250 |
| products | 110 |
State what is meant by the term activation energy.
Calculate the activation energy for this reaction.
Calculate the energy given out during the reaction.
Explain, using the table, whether the combustion of methane is exothermic or endothermic.
Explain why a spark is needed to start the reaction.
53 exam-style questions on Edexcel GCSE Chemistry 8.2 Heat energy changes in chemical reactions, covering 8.2.1 Exothermic and endothermic changes, 8.2.2 Bond breaking, bond making and overall energy change, 8.2.3 Calculating energy change from bond energies, and 8.2.4 Activation energy and reaction profiles. Each one has a worked solution and a mark scheme showing where the marks go.