A student adds magnesium ribbon to dilute hydrochloric acid in a test tube. The reaction is exothermic. What happens to the temperature of the reaction mixture, and why?
It increases, because energy is transferred to the surroundings
It increases, because energy is taken in from the surroundings
It decreases, because energy is transferred to the surroundings
It decreases, because energy is taken in from the surroundings
39 exam-style questions on AQA GCSE Chemistry 5.1 Exothermic and endothermic reactions, covering 5.1.1 Energy transfer during exothermic and endothermic reactions, 5.1.2 Reaction profiles, and 5.1.3 The energy change of reactions. Each one has a worked solution and a mark scheme showing where the marks go.