lattice energy

Lattice energy

the energy released when an ionic solid is formed from its ions

enthalpy

change in heat (delta H)

modified coulomb’s law Equation for lattice energy

lattice energy = k (Q1Q2 / r)

k

proportionality constant that depends on the structure of the solid and the electron configuration of the ions

Q1 and Q2

charges of ions

r

distance between ion centers (in nanometers)

importance of equation

lattice energy for an ionic solid w/ 2+ and 2- ions should be four times greater than the lattice energy for an ionic solid w/ 1+ and 1- ions

relationship w/ r value

small ions (little “r” value) is greater than the lattice energy for an ionic compound w/ large ions

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