Now let's look at the following reaction. Suppose a red molecule must react with an orange molecule to produce a red orange product. Now, suppose we dissolve these guys in a liquid. So in liquid reactants are dissolved in a solvent, like, for example, water, which ends up predominating the solution. Therefore, most of the collisions in liquids occur between solvent and solute. And this means that even though the collisions occur more frequently in liquid than acoustic solutions, a lot of those collisions are between solvent and soluble molecules.