Lattice energy is defined as the energy
- A. needed to melt one mole of an ionic solid
- B. needed to vaporise one mole of a liquid
- C. released when one mole of an ionic crystal is formed from its gaseous ions
- D. absorbed when an electron is added to a gaseous atom
Explanation
Bringing gaseous ions together into an ordered lattice releases a large amount of energy, so lattice energy is strongly exothermic and is a direct measure of the strength of the ionic bonding. It cannot be measured directly and is obtained instead from a Born Haber cycle using Hess's law. Energy absorbed when an electron is added to a gaseous atom is electron affinity.