Toss a few whole almonds in a jar full of hazelnuts. Shake. The nuts bounce against each other, but they don’t react. That’s how some people think of reactions happening inside liquids. The solutes (almonds) react with each other in a sea of solvent (hazelnuts). But a new study shows that this is not always the case for real chemical reactions. Under the right conditions, the solvent can change the chemical identity of the solute.