[KurzickMushroom]

If I increase the temperature of a solution, the general trend is that I can put more g/mol of the substance in without saturating the solution. I was wondering why temeprature causes this. I have learned about how ionic bonds break down and bond with polar water molecules. Does it have any effect on these bonds?(ex: They break them down faster)

[cliverlong]

If I increase the temperature of a solution, the general trend is that I can put more g/mol of the substance in without saturating the solution. I was wondering why temeprature causes this. I have learned about how ionic bonds break down and bond with polar water molecules. Does it have any effect on these bonds?(ex: They break them down faster)

As you wrote the general trend.

Now I have found a couple of sites which give examples of solubility of certain substances decreasing with temperature

http://www.elmhurst.edu/~chm/vchembook/174temppres.html
http://www.preparatorychemistry.com/Bishop_solubility_temperature.htm

I think the explanation is probably an application of Le Chatelier's principle.

First, consider a saturated solution is a dynamic equilibrium where the dissolved particles and solid phase are constantly interchanging state.
Next  we determine if the overall enthalpy of solution if endothermic or exothermic.
So we apply Le Chatelier to explain chnage in behaviour when the external condition (temp) changes
If solution process is exothermic overall ,  then raising temperature will encourage solution to "go into reverse" (an application of Le Chatelier) and solubility will decrease with temp.
Conversely, if solution process is endothermic overall , then raising temperature will encourage solution to "go in forward direction" to absorb the increase in temperature (an application of Le Chatelier) and solubility will increase with temp.


A full explanaiton will probably also involve a consideration of entropy, i.e. is solution more dissordered than the solid? And hence the (Gibbs) Free energy may be a parameter better suited than enthalpy to explaining the direction of solubiity upon change in temperature.

Hope that is of some help.

Clive