A student uses a spirit burner to determine the enthalpy change of combustion of methanol. They heat a beaker of water using the burner, and they decide to place draught shields around the apparatus.
State why using draught shields helps to give a more accurate value for the temperature change of the water.
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.