[Boron Moron]

I have been wondering for some time why the relationship between solubility and temperature is non-linear. Does anyone know of any resources that would help explain the reason for the non-linear nature of these curves?

Thanks.

[mjc123]

Think of the equilibrium constant K_sol. We know (I hope) that lnK_sol = -ΔG_sol°/RT = -ΔH_sol°/RT + ΔS_sol°/R
Thus dlnK_sol/dT = ΔH_sol°/RT² (assuming ΔH and ΔS are constant with temperature, which is usually true to a first approximation, over a relatively small temperature range)
The RHS is fairly constant over a small temperature range, hence it is lnK, not K, that varies linearly with temperature.

[Old_Doc48]

I have been wondering for some time why the relationship between solubility and temperature is non-linear. Does anyone know of any resources that would help explain the reason for the non-linear nature of these curves?

Thanks.

What evidence do you have that would lead you to believe solubility and temperature is linear?