CHAPTER 20: Lattice  Energy

• Introduction to Lattice Energy
• Born-Haber Cycles
• Ion Polarisation
• Enthalpy Changes in Solutions

Learning outcomes:

• explain and use the term lattice energy (∆H negative, e. gaseous ions to solid lattice).
• explain, in qualitative terms, the effect of ionic charge and of ionic radius on the numerical magnitude of a lattice energy
• apply Hess’ Law to construct simple energy cycles, and carry out calculations involving such cycles and relevant energy terms, with particular reference to:
  • the formation of a simple ionic solid and of its aqueous solution
  • Born-Haber cycles (including ionisation energy and electron affinity).
• interpret and explain qualitatively the trend in the thermal stability of the nitrates and carbonates in terms of the charge density of the cation and the polarisability of the large anion.
• interpret and explain qualitatively the variation in solubility of Group II sulfates in terms of relative magnitudes of the enthalpy change of hydration and the corresponding lattice energy