Aqueous solution
An
aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending to the relevant formula. For example, a solution of ordinary table salt, or sodium chloride, in water would be represented as NaCl. The word
aqueous means pertaining to, related to, similar to, or dissolved in water. As water is an excellent solvent and is also naturally abundant, it is an ubiquitous solvent in chemistry. Substances that are
hydrophobic often do not dissolve well in water, whereas those that are
hydrophilic do. An example of a hydrophilic substance is sodium chloride. Acids and bases are aqueous solutions, as part of their Arrhenius definitions. The ability of a substance to dissolve in water is determined by whether the substance can match or exceed the strong attractive forces that water molecules generate between themselves. If the substance lacks the ability to dissolve in water the molecules form a precipitate. Aqueous solutions that conduct electric current efficiently contain strong electrolytes, while ones that conduct poorly are considered to have weak electrolytes.