Lattice Energy Formula – Equation and Problem Solved with Example

The lattice energy could be defined in two ways in Chemistry. Let us discuss the both of definitions one by one in this blog post. The overall potential energy of a chemical compound is also named as the lattice energy and it can be defined in terms of electrostatic or repulsive energy.

With the help of Born-Lande equation, the lattice energy is provided. This is possible to make the Lattice energy when two oppositely charged ions in gaseous state attract each other and responsible to make the ionic solid ahead. When two ions react together, it will release the exothermic heat. In general, the lattice energy is quite complicated process and can be simplified as the Coulomb’s law as given below –

Lattice Energy Formula

\[\ LE =\frac{KQ1Q2}{r}\]
LE = lattice energy.
K = 2.31 X 10-10 J.nm
Q1 and Q2 are ion charges in numeric terms, and r is the total distance between ion centers.

Based on one more definition of the Lattice Energy (LE), it is required to break down the ionic solids and converting its components to the atoms of gaseous ions. In this case, the value of Lattice energies would always be positive because it is an endothermic reaction.

Usually, the ionic solids are highly stable in nature but enthalpy of formation cannot account for its stability. The ionic compounds could gain that extra stability with the help of Lattice Energy in the solid structure. However, there is not a proper technique to measure the Lattice energy value directly. With the help of Born-Haber cycle, you can always understand or measure the lattice energies of ionic solids quickly as needed.