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Key Equations

Key Equations

formal charge=# valence shell electrons (free atom)−# lone pair electrons−12# bonding electronsformal charge=# valence shell electrons (free atom)−# lone pair electrons−12# bonding electrons
Bond energy for a diatomic molecule: XY(g)⟶X(g)+Y(g)DX–Y=ΔH°XY(g)⟶X(g)+Y(g)DX–Y=ΔH°
Enthalpy change: ΔH = ƩDbonds broken – ƩDbonds formed
Lattice energy for a solid MX: MX(s)⟶Mn+(g)+Xn−(g)ΔHlatticeMX(s)⟶Mn+(g)+Xn−(g)ΔHlattice
Lattice energy for an ionic crystal: ΔHlattice=C(Z+)(Z−)RoΔHlattice=C(Z+)(Z−)Ro