Which of the following statements correctly describes lattice energy?

• A. It is the energy change when a solid melts to form a liquid.
• B. It is the energy required to break a covalent bond in a molecule.
• C. It is the energy absorbed when an ionic solid dissolves in water.
• D. It is the energy released when gaseous ions combine to form an ionic solid.

Answer: (D)

Verified step by step guidance

1. Understand that lattice energy refers to the energy change associated with the formation of an ionic solid from its gaseous ions.
2. Recall that lattice energy is typically defined as the energy released when one mole of an ionic crystalline compound forms from its constituent gaseous ions, indicating an exothermic process.
3. Recognize that lattice energy is not related to melting (which involves solid to liquid phase change), covalent bond breaking (which involves molecular bonds), or dissolution in water (which involves solvation and hydration energies).
4. Identify that the correct description of lattice energy is: the energy released when gaseous ions combine to form an ionic solid.
5. Confirm that this energy is a measure of the strength of the ionic bonds in the solid lattice and is important for understanding the stability and properties of ionic compounds.