dissolving aluminium oxide in cryolite
 

can anyone tell me how the aluminium oxide dissolve in molten cryolite??? :wink:

In the same way as anything dissolves in anything else - by forming bonds with the solvent particles.

The Al3+ ions from the aluminium oxide are 'solvated' by the molten AlF4- ions from the molten cryolite and carried into solution. Similarly the oxide ions are carried into soolution solvated by the sodium ions of the cryolite.

If the energy is favourable (and in this case it must be) ions will dissolve by forming bonds with the solvent particles - in this case Na+ and AlF4- ions.