Stability of Ionic Compounds

Ionic compounds are formed between a metal and a non-metal. They are composed of ions held together by electrostatic forces of attraction. The stability of an ionic compound depends on various factors such as the size of the ions, the charge on the ions, and the lattice energy.

Lattice Energy

Lattice energy is defined as the energy required to convert one mole of an ionic compound into its constituent ions in the gaseous state. It is a measure of the strength of the ionic bonds in the compound. The higher the lattice energy, the stronger the ionic bonds and the more stable the compound.

Size of the Ions

The size of the ions also affects the stability of the compound. Generally, smaller ions form more stable compounds because they can pack more closely together, resulting in a stronger ionic bond.

Charge on the Ions

The charge on the ions also plays a role in the stability of the compound. The higher the charge on the ions, the stronger the ionic bond and the more stable the compound.

Answer

Of the given options, LiF has the highest lattice energy due to the high charges on the ions and the small size of the ions. This high lattice energy makes LiF the most stable compound among the given options. Hence, the correct answer is option 'A', LiF.

LiCl, LiBr, and LiI have progressively larger anions and thus smaller lattice energies, making them less stable than LiF.