An aqueous solution's a solution in which the solvent's water. It's usually shown in chemical equations by appending (aq) to the relevant formula. The word aqueous means pertaining to, related to, similar to, or dissolved in water. As water's an excellent solvent as well as naturally abundant, it's a ubiquitous solvent in chemistry. Substances that don't dissolve well in water are called hydrophobic ('water fearing') whereas those that do are known as hydrophilic ('water-loving'). An example of… (More on Aqueous)