nonpolar-nonpolar interactions
Nonpolar-nonpolar interactions occur when two nonpolar liquids are mixed. An example of this is the interaction between toluene and octane see Figures above and below . The interactions between a molecule of toluene and a molecule of octane are relatively weak, but so are the toluene-toluene and octane-octane interactions. Because no strong intermolecular forces like those between water molecules need to be broken for mixing to occur, no strong interactions need to be formed in order for mixing to be a favorable process. Toluene and octane will form a homogeneous mixture. The phrase "like dissolves like" applies to these mixtures as well. In this case, nonpolar dissolves nonpolar.