Hydrogen reacts with bromine to form hydrogen bromide.
H2+Br2→2HBr\text{H}_2 + \text{Br}_2 \rightarrow 2\text{HBr}H2+Br2→2HBr
The total energy needed to break bonds in the reactants is 629 kJ/mol.
The total energy released when bonds form in the products is 732 kJ/mol.
Which statement about the overall energy change of this reaction is correct?
The overall energy change is negative and the reaction is endothermic
The overall energy change is positive and the reaction is endothermic
The overall energy change is positive and the reaction is exothermic
The overall energy change is negative and the reaction is exothermic
85 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.