Born-Haber Blues

I try to do these calculations and duff them up every time...
Enthalpies of formation and lattice enthalpies and electron affinities and such...

Can anyone explain how to do them to me?
:confused:

Reply 1

Tes

For enthalphy changes always use a Hess diagram and draw the reactants and products

Here i drew this for a mate once:

Basically draw the overall equation and then draw steps from the reactants to the products. Then add all the enthalphy changes onto the diagram making sure the ARROWS ARE THE RIGHT WAY ROUND!!!!! (Ive done it many a time) and then follow the path adding up enthalphy changes as you go along just add it if the arrow is the same way and take it away if its going the wrong way, dunno about the other ones sorry.