In chemistry, neutralization, or neutralisation (see spelling differences) is a chemical reaction in which an acid and a base react to form a salt. Water is frequently, but not necessarily, produced as well. Neutralizations with Arrhenius acids and bases always produce water:
Y and X represent a monovalent cation and anion respectively. XY would be the salt produced. An example reaction of this form is the reaction between sodium hydroxide and hydrochloric acid, where sodium is Y and chlorine is X:
Water and common table salt are produced.
The reaction can also be considered as a net ionic equation:
This representation is inaccurate, however, as the hydrogen ion (H+) does not actually occur in solution during a neutralization. In fact, the hydronium ion (H3O+) occurs, produced by the following reaction:
Considering the hydronium ion, the actual net ionic reaction occurring is:
In non-aqueous reactions, water is less likely to be formed; however, there is always a donation of protons (see Brønsted-Lowry acid-base theory). Since a variety of definitions of acids and bases exist, a variety of reactions may be considered neutralization reactions. All of the following may be considered neutralization reactions under different definitions:
Often, neutralization reactions are exothermic (the enthalpy of neutralization). For example, the reaction of sodium hydroxide and hydrochloric acid. An example of an endothermic neutralization is the reaction between sodium bicarbonate (baking soda) and acetic acid (vinegar).
Neutralization means to neutralize, in chemistry the neutral PH of 7 would be counted as neutral.
Equal numbers of moles of acid and base are needed for neutralization reactions. Hence, the formula becomes
where a is the number of acidic hydrogens and b is the constant that tells you how many H3O+ ions the base can accept. [A] denotes the concentration of acid and [B], the concentration of base. Va is the volume of acid and Vb is the volume of base.