The amount of energy released during formation of one mole of ionic compound from its constituent ions is called _____.
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Lattice Energy
Lattice energy is the energy released when one mole of an ionic compound is formed from its gaseous ions (for example, Na+ and Cl− ions coming together to form solid NaCl). The larger the lattice energy, the more stable the ionic crystal.
Why the other options are incorrect
Option (1) Ionization Potential — Incorrect. It is the energy needed to remove an electron from a gaseous atom.
Option (2) Hydration Energy — Incorrect. It is the energy released when gaseous ions are surrounded by water molecules.
Option (4) Electronegativity — Incorrect. It is the tendency of an atom in a bond to attract the shared electrons; it is not an energy at all.