Base (chemistry) increase the hydronium (HO) concentration in water, whereas bases reduce this concentration. A reaction between an acid and base is called neutralization. In a neutralization reaction, an aqueous solution of a base reacts with an aqueous solution of an acid to produce a solution of water and salt in which the salt separates into its component ions. If the aqueous solution is saturated with a given salt solute, any additional such salt precipitates out of the solution. The notion of a base as a concept in chemistry was first introduced by the French chemist Guillaume François Rouelle in 1754. He
Saturation (chemistry) point of saturation in hot solvent, then as the solvent cools and the solubility decreases, excess solute precipitates. Impurities, being present in much lower concentration, do not saturate the solvent and so remain dissolved in the liquid. If a change in conditions (e.g. cooling) means that the concentration is actually higher than the saturation point, the solution has become supersaturated. In physical chemistry, when referring to surface processes, saturation denotes the degree at which a binding site is fully occupied. For example, base saturation refers to the fraction of exchangeable cations that are base cations. In biochemistry, the term saturation