mathemetical determination of solublity

[Physicsfan]

Hi. Is it possible to determine weather an ionic compound is soluble or insoluble in water using the formula [imath]\frac{1}{4\pi\epsilon} \frac{q_1q_2}{r^2}[/imath]

?

[Tartaglia]

Well you can determine the electrostatic attraction/repulsion part of the lattice energy due to point charges (this involves a constant called the Madelung constant), though not the repulsion due to overlapping electron clouds. The solvation energy is largely a function of the polarising power of the ions, which is determined by charge density. There are also obviously entropy considerations

[John Cuthber]

All materials are soluble ( provided they don't react with the solvent).

The question is how soluble are they?

[Physicsfan]

All materials are soluble ( provided they don't react with the solvent).

The question is how soluble are they?

lead nitrate is soluble but lead sulphate and lead carbonate are not soluble. They

precipitate in water.

 

I dont know if my reasoning is correct, but according to me an electrovalent compound is insoluble in water when the elctrostatic force between the two ions,

exceeds the electrostatic force exerted by the hydrogen and Oxygen ions of water(polar solvent) on the respective ions.

 

according to me , the electrostatic force betwwen the two ions should depend on atomic radii of each ion and the charge.

Edited June 9, 2010 by Physicsfan