Increase in Solubility of a Gas with an Increase in Temperature On the UC Davis ChemWiki I read, "some gases have an increase in solubility with an increase in temperature."  
I understand why this is applicable to solids in liquids such as water, but why is it applicable as well as for gases in liquids?
 A: If the dissolution of the gas absorbs heat in order to occur (e.g. $N_2$ gas dissolving in benzene):
$$Undissolved\ N_2 + Heat \rightleftharpoons Dissolved\ N_2$$
then raising the temperature will add more heat and by Le Chatelier's principle force the reaction to the right. In other words, if the dissolution requires heat to occur and you add more heat, more dissolution will occur. This corresponds to an increase in solubility with an increase in temperature.
If the dissolution of the gas produces heat when it occurs (e.g. $O_2$ gas dissolving in water):
$$Undissolved\ O_2 \rightleftharpoons Dissolved\ O_2 + Heat$$
as raising the temperature adds more heat, having the extra heat around will instead allow more gas to leave the dissolved state. This corresponds to a decrease in solubility with a decrease in temperature.
The model that is used to explain whether the gas absorbs or produces heat upon dissolving in a liquid solvent is based on the bonding of the liquid molecules with each other vs. with the gas molecules.
