List the individual steps used in constructing a Born–Haber cycle for the formation of BaI₂ from the elements. Which of the steps would you expect to be exothermic?

Key Concepts

Born-Haber Cycle

The Born-Haber cycle is a thermodynamic cycle that relates the lattice energy of an ionic compound to the enthalpy changes involved in its formation from the constituent elements. It provides a systematic way to calculate the lattice energy by considering the various steps, including sublimation, ionization, and electron affinity, that occur when forming an ionic compound from its elements.

Lattice Energy

Lattice energy is the energy released when gaseous ions combine to form an ionic solid. It is a crucial factor in determining the stability of ionic compounds. In the context of the Born-Haber cycle, lattice energy is typically a large exothermic value, indicating that the formation of the ionic lattice from gaseous ions is energetically favorable.

Enthalpy Changes

Enthalpy changes refer to the heat absorbed or released during a chemical reaction at constant pressure. In the Born-Haber cycle, various steps involve enthalpy changes, such as the enthalpy of sublimation, ionization energy, and electron affinity. Understanding which steps are exothermic (release heat) or endothermic (absorb heat) is essential for predicting the overall energy change in the formation of the compound.