Heat energy changes in chemical reactions

Understand that heat energy changes accompany processes like dissolving salts, neutralisation, displacement, and precipitation, and that these changes can be measured as temperature variations in solution.

Describe an exothermic reaction as a chemical change in which heat energy is released into the surroundings.

Describe an endothermic reaction as a chemical change in which heat energy is absorbed from the surroundings.

Recall that the breaking of chemical bonds is an endothermic process, whereas the formation of chemical bonds is an exothermic process.

Determine whether a reaction is overall exothermic or endothermic by comparing the heat energy released during bond formation to the heat energy required for bond breaking.

Calculate the overall energy change of a chemical reaction using provided bond energies (in kJ mol^-1).

Explain the concept of activation energy in the context of chemical reactions.

Draw, label, and interpret reaction profile diagrams for both endothermic and exothermic reactions, correctly identifying the activation energy.