A student repeats an exothermic experiment and obtains temperature rises of 6.8, 7.0 and 12.4 ∘C12.4\,^\circ\mathrm{C}12.4∘C. What is the best way to process these results?
Average all three results to give 8.7 ∘C8.7\,^\circ\mathrm{C}8.7∘C
Use only 12.4 ∘C12.4\,^\circ\mathrm{C}12.4∘C, as it lost the least heat
Average only the lowest and the highest of the three results
Treat 12.4 ∘C12.4\,^\circ\mathrm{C}12.4∘C as anomalous; average the other two
94 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.