Applications of lattice energies

We now consider some typical applications of lattice energies further examples are given in later chapters. 

Self-study exercises Use data from the Appendices. 

15 Lattice energy calculated versus experimental values 

---

By considering the definition of lattice energy, it is easy to see why these quantities are not measured directly. However, an associated lattice enthalpy of a salt can be related to several other quantities by a thermochemical cycle called the Born-Haber cycle. If the anion in the salt is a haUde, then all the other quantities in the cycle have been determined independently the reason for this statement will become clearer when we look at applications of lattice energies in Section 5.16. 

Simple and more advanced calculations of lattice energies many applications. 

The theory of ionic crystals discussed above in its application to lattice energy has also been applied to other physical properties of these crystals. We have already seen how the compressibility of a crystal may be deduced, and have shown that experimental values for this quantity... 

Born-Haber cycle A thermodynamic cycle derived by application of Hess s law. Commonly used to calculate lattice energies of ionic solids and average bond energies of covalent compounds. E.g. NaCl ... 

For such a condition of equilibrium to be reached, the atoms must acquire sufficient energy to permit their displacement at an appreciable rate. In the case of metal lattices, this energy can be provided by a suitable rise in temperature. In the application of coatings the diffusion process is arrested at a suitable stage when there is a considerable solute concentration gradient between the surface and the required depth of penetration. 

---