AQA A-level CHEMISTRY Paper 3 2026 (36pages)

A student does an experiment to determine a value for the enthalpy of solution for ammonium nitrate. The student uses this method. • Measure 25.0 cm3 of distilled water in a measuring cylinder. • Pour the water into a beaker. • Record the temperature of the water in the beaker. • Add 4.00 g of solid NH4NO3 to the water in the beaker. • Stir the solution and record the lowest temperature reached. Table 2 shows the student’s results. Table 2 Initial temperature / °C 20.2 Lowest temperature / °C 12.2 Calculate the enthalpy of solution, in kJ mol−1, for ammonium nitrate in this experiment. Assume that the specific heat capacity of the solution, c = 4.18 JK−1 g−1 Assume that the density of the solution = 1.00 gcm−3