Some points to consider

At SL/HL this topic looks at the enthalpy changes that occurs during chemical reactions and goes on to consider energy from fuels including fossil fuels, biofuels and fuel cells. We use the word enthalpy and not heat energy but certainly for Standard Level (and in truth also at Higher Level) the distinction between the two is not important. The IB does emphasise that most measurements for ∆H are done under standard conditions but not the fact that ∆H should only be used as the term when the pressure remains constant.

Through your practical work you should understand the need for E = mass x specific heat capacity x temperature rise rather than just fit numbers into a remembered equation (Q = mcΔT). You can also gain an understanding of what is meant by an exothermic reaction and the fact that not all enthalpy changes can be determined directly. You will also see that Hess’s Law is simply another way of stating the First Law of Thermodynamics (Law of Conservation of Energy).

What is worth realising throughout all of the sub-topics is the need to consider the states. I have even seen teachers, text book authors and lecturers at university (let alone students) use average bond enthalpies wrongly. For example, when determining the enthalpy change for the hydrogenation of unsaturated fats you need to understand that you cannot just use average bond enthalpies as these only refer to the gaseous state whereas unsaturated fats are normally liquids under standard conditions. Changing state involves an enthalpy change.

Another example where mistakes are often made is in calculations involving enthalpies of combustion. The definition of standard enthalpy of combustion involves water in the liquid state at 298 K. Using just average bond enthalpies is bound to give the wrong answer unless the enthalpy change for the change of state in going from gaseous to liquid water is also included.

The combustion of natural gas - under standards conditions the water produced is in the liquid state.

At Higher Level the Born-Haber cycle can be considered as ‘just another enthalpy cycle’ although you will need to understand the importance of the size of the lattice enthalpy in the formation and reactions of ionic compounds. Where Higher Level really differs is that it brings in Gibbs energy and the concepts of entropy and spontaneity. If you really understand and can apply the equation ∆G^⦵ = ∆H^⦵ −T∆S^⦵, understand the relationship between ∆G^⦵ and the equilibrium constant, K_c and also the expression ΔG^⦵ = −nFE^⦵_cell  for voltaic cells then you will be well on your way to mastering chemistry.