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## Homework Statement

What is the lattice energy of KI? Given the information below.

Heat of formation for KI = -328 kJ/mol

Heat of sublimation for K = 89.20 kJ/mol

Ionization energy for K = 419 kJ/mol

Bond dissociation energy for I

_{2}= 149 kJ/mol

Electron affinity for I = - 295 kJ/mol

Heat of sublimation for I2 = 48.30 kJ/mol

I used Born-Haber's law: Delta H of formation = .5*Delta Dissociation + Delta H of sublimation + Ionization Energy + Electron Affinity + Lattice Energy

## Homework Equations

Born-Haber's law = Delta H of formation = .5*Delta Dissociation + Delta H of sublimation + Ionization Energy + Electron Affinity + Lattice Energy

## The Attempt at a Solution

I used Born-Haber's law: Delta H of formation = .5*Delta Dissociation + Delta H of sublimation + Ionization Energy + Electron Affinity + Lattice Energy

-328 = (89.20 - 48.30) + .5 (149) + 419 - 295 + Lattice Energy

Lattice Energy = -567.4 (Which is wrong; it should be a positive answer)