Lattice energy (ΔHlattice)

Definition

Lattice energy ($\Delta H_{lattice}$) is the energy released when one mole of an ionic crystalline compound is formed from its constituent ions in the gas phase. It is a measure of the strength of the bonds in that ionic compound.

5 Must Know Facts For Your Next Test

1. Lattice energy is usually expressed in kilojoules per mole (kJ/mol).
2. A higher lattice energy indicates a more stable ionic compound with stronger ionic bonds.
3. Lattice energy can be calculated using the Born-Haber cycle, which involves several steps including ionization energy and electron affinity.
4. The magnitude of lattice energy increases with increasing charge on the ions and decreasing ionic radii.
5. Coulomb's Law relates lattice energy to the charges on the ions and the distance between them: $E = k \frac{q_1 q_2}{r}$.

Review Questions

Related terms

Born-Haber Cycle:

A thermodynamic cycle that describes the formation of an ionic compound from its constituent elements.

Ionization Energy:

The amount of energy required to remove an electron from a gaseous atom or ion.

Electron Affinity:

The change in energy when an electron is added to a neutral atom in the gas phase to form a negative ion.