An environmental chemist uses a simple spirit burner setup with a glass beaker containing 200 cm3 of water to find the enthalpy of combustion of liquid pentan-1-ol. After burning a certain amount of the fuel, the temperature of the water increased by 24∘C24^{\circ}\text{C}24∘C.
The mass of pentan-1-ol burned during the experiment was significantly larger than the mass predicted using theoretical bond enthalpies.
Identify one experimental reason why the measured mass of pentan-1-ol burned was higher than the theoretical value.
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.