Provide an example of the lattice energy of different ionic compounds.

The lattice energy of ionic compounds varies depending on the size and charge of the ions.

Lattice energy is the energy required to separate one mole of an ionic compound into its gaseous ions. It is a measure of the strength of the ionic bond between the ions in the crystal lattice. The lattice energy is influenced by the size and charge of the ions. The smaller the ions and the higher the charge, the stronger the ionic bond and the higher the lattice energy.

For example, the lattice energy of sodium chloride (NaCl) is -787 kJ/mol. This is because the sodium ion (Na+) is small and has a charge of +1, while the chloride ion (Cl-) is also small and has a charge of -1. The strong attraction between the oppositely charged ions results in a high lattice energy.

In contrast, the lattice energy of calcium oxide (CaO) is -3,330 kJ/mol. This is because the calcium ion (Ca2+) is larger than the sodium ion and has a charge of +2, while the oxide ion (O2-) is larger than the chloride ion and has a charge of -2. The larger ions and higher charges result in a stronger ionic bond and a higher lattice energy.

Overall, the lattice energy of ionic compounds is an important factor in determining their physical and chemical properties, such as melting and boiling points, solubility, and reactivity.