We recently published a paper (Patrick Yee, Jindal K. Shah and Edward J. Maginn, “State of Hydrophobic and Hydrophilic Ionic Liquids in Aqueous Solutions: Are the Ions Fully Dissociated?”, Journal of Physical Chemistry B, 2013, 117, 12556-12566. DOI: 10.1021/jp405341m) in which simulations showed that hydrophobic ionic liquids can remain associated in aqueous solutions, even under highly dilute conditions. Potentials of mean force calculations enabled us to estimate associate constants for a range of different ionic liquids. Somewhat surprisingly, we find that ionic liquid salts do not behave like conventional alkali halide salts. The ions of ionic liquids can remain associated is aqueous solutions due to favorable van der Waals interactions between the ions.