How dissolving happens

Why do some things dissolve in one solvent and not another? For example, oil and water don’t mix to form a solution, but oil does dissolve in gasoline.

There’s a general rule of solubility that says like-dissolves-like in regards to polarity of both the solvent and solutes. A polar material is composed of covalent bonds with a positive and negative end of the molecule. (For a rousing discussion of water and its polar covalent bonds. A polar substance such as water dissolves polar solutes, such as salts and alcohols. Oil, however, is composed of largely nonpolar bonds, so water doesn’t act as a suitable solvent for oil.