KD3203 2020-12-20 18:01
Standard lattice energy change
When one mole of gaseous ions
Forms ionic compound at 2 9 8 K
And 100 KPa, standard conditions
Add given enthalpies, use Hess Law in Born Haber Cycle
Then we can get the experimental lattice energy
But there’s one more, theoretical
By principles of electrostatics
A large difference, more covalent
Small charged cations have large polarising power
Anion with high charge and a larger size
Will have same effect too, more polarising
Solution enthalpy, when a mole of ionic solid
Dissolves in H2O, forms infinitely dilute solution
Dilution effect affects value
1 mole hydrated by H2O
Ion dipole, it’s hydration
It’s always negative, more with higher charge
Stronger interaction, decrease down a group
Lattice plus solution, by the Born Haber cycle
Equates the enthalpy change of hydration of the ions
It’s enthalpy in a lattice (x2)