Recall that changes in heat energy accompany the following changes:
a) salts dissolving in water b) neutralisation reactions c) displacement reactions d) precipitation reactions
and that, when these reactions take place in solution, temperature changes can be measured to reflect the heat changes
Describe an exothermic change or reaction as one in which heat energy is given out
Describe an endothermic change or reaction as one in which heat energy is taken in
Recall that the breaking of bonds is endothermic and the making of bonds is exothermic
Recall that the overall heat energy change for a reaction is:
a) exothermic if more heat energy is released in forming bonds in the products than is required in breaking bonds in the reactants b) endothermic if less heat energy is released in forming bonds in the products than is required in breaking bonds in the reactants
Calculate the energy change in a reaction given the energies of bonds (in kJ mol–1)
Explain the term activation energy
Draw and label reaction profiles for endothermic and exothermic reactions, identifying activation energy