Electrostrictive Pressure near an Ion in Solution

The molar volume of water in the natural state is 18 cm moE but if water molecules are close-packed in the liquid state, this volume would become only 12cm mor, a reduction of 33%. Thus, the volume available for the effects of electrical constriction by ions on water molecules is as much as 6 cm mol .  

It is easy to calculate a typical pressure exated by an ion on a water molecule in the first hydration shell. Thus, the energy ofinteraction of an ion ofradius r on a water molecule ofradius r is 

The force calculated here is upon a water molecule in the hydration shell. If 

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