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In chemistry, neutralization (US spelling) or neutralisation (UK spelling), is a chemical reaction in which an acid and a base react quantitatively with each other. In a reaction in water, neutralization results in there being no excess of hydrogen or hydroxide ions present in solution. The pH of the neutralized solution depends on the acid strength of the reactants. Neutralization is used in many applications. == Meaning of "neutralization" == In the context of a chemical reaction the term neutralization is used for a reaction between an acid and a base or alkali. Historically, this reaction was represented as :acid + base = salt + water For example: :HCl + NaOH → NaCl + H2O The statement is still valid as long as it is understood that in an aqueous solution the substances involved are subject to dissociation, which changes the substances ionization state. The arrow sign, →, is used because the reaction is complete, that is, the said neutralization is a quantitative reaction. A more general definition is based on Brønsted–Lowry acid–base theory. :AH + Bz → A− +BHz+1 AH represents an acid and B represents a base. z is an electric charge; negative for an anion, zero, or positive for a cation. When the reaction takes place in water and the base is the hydroxide ion, OH-, the reaction can be written as :AH + OH− → A− + H2O After an acid 'neutralization', there are no molecules of AH (or hydrogen ions produced by dissociation of the molecule) left, since all the acid molecules present initially in a neutral form are then ionized, i.e., charged, A−; the term 'acid neutralization' therefore implies acid (effects) rather than charge neutralization. In electrical terms, 'acid neutralization' thus corresponds to acid ionization. In the reaction, the amount of base added must moreover equal the amount of acid present initially. This amount of base is said to be the equivalent amount. In a titration of an acid with a base, the point of neutralization can also be called the equivalence point. The quantitative nature of the neutralization reaction is most conveniently expressed in terms of the concentrations of acid and alkali. At the equivalence point: :volume (acid) × concentration (H+ ions from dissociation) = volume (base) × concentration (OH− ions) In general, for an acid AHn at concentration c1 reacting with a base B(OH)m at concentration c2 the volumes are related by: : n v1 c1 = m v2 c2 The concept of neutralization is not limited to reactions in solution. For example, the reaction of limestone with acid such as sulfuric acid is also a neutralization reaction. :()CO3(s) + H2SO4(aq) → ()SO4(s) + CO2(g) + H2O Such reactions are important in soil chemistry. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Neutralization (chemistry)」の詳細全文を読む スポンサード リンク
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