Neutralization is a chemical reaction, also called a water forming reaction, in which an acid and a base or alkali (soluble base) react and produce a salt and water. In other words, it can be said that neutralization is the combination of hydrogen ions H⁺ and hydroxide ions OH⁻ (or oxide ions O²⁻) to form water molecule H₂O. In the process, a salt is formed. Neutralization is exothermic, meaning it produces heat. A chemical reaction occurs when vapours of hydrogen chloride and ammonia meet to form a cloud of a new substance, ammonium chloride Chemical reaction is a process that results in the interconversion of chemical substances [1]. The substance or substances initially involved in a chemical reaction are called reactants. ... For other uses, see Acid (disambiguation). ... A bases in chemistry is a chemical substance which has a free pair of electrons to bind a Hydrogen ion commonly referred to as a proton (IUPAC definition). ... A magnified crystal of a salt (halite/sodium chloride) A salt, in chemistry, is any ionic compound composed of cations (positively charged ions) and anions (negative ions) so that the product is neutral (without a net charge). ... Water is a tasteless, odourless substance that is essential to all known forms of life and is known as the universal solvent. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ... ... Hydroxide is a polyatomic ion consisting of oxygen and hydrogen: OH− It has a charge of −1. ... ... An oxide is a chemical compound of oxygen with other chemical elements. ... ... This article describes water from a scientific and technical perspective. ... A magnified crystal of a salt (halite/sodium chloride) A salt, in chemistry, is any ionic compound composed of cations (positively charged ions) and anions (negative ions) so that the product is neutral (without a net charge). ... Exothermic means to release energy in the form of heat. ... In physics, heat, symbolized by Q, is defined as energy in transit. ...

Most generally, the following occurs:

acid + base → salt + water

For example, the reaction between hydrochloric acid and sodium hydroxide solutions: The chemical compound hydrochloric acid is the aqueous (water-based) solution of hydrogen chloride (HCl). ... Sodium hydroxide (NaOH), also known as lye or caustic soda, is a caustic metallic base. ...

hydrochloric acid + sodium hydroxide → sodium chloride + water

HCl(aq) + NaOH(aq) → NaCl(aq) + H₂O(l)

Since the HCl and NaOH dissociate into ions in solution, the ionic equation is: An ion is an atom or group of atoms that normally are electrically neutral and achieve their status as an ion by loss (or addition) of (an) electron(s). ...

H⁺(aq) + Cl⁻(aq) + Na⁺(aq) + OH⁻(aq) → Na⁺(aq) + Cl⁻(aq) + H₂O(l)

And since the sodium and chloride ions are just spectator ions not involved in the reaction, the net equation becomes: A spectator ion is a ion in a chemical reaction that remains unchanged after the reaction has occured compared to beforehand. ...

H⁺(aq) + OH⁻(aq) → H₂O(l) : Δ_rH = −55.90 kJ mol⁻¹

This illustrates why neutralization reactions are also referred to as water forming reactions. Of course the sodium and chloride ions are still in solution so the result is pH neutral salt water. pH is a measure of the acidity of a solution in terms of activity of hydrogen (H+). For dilute solutions, however, it is convenient to substitute the activity of the hydrogen ions with the molarity (mol/L) of the hydrogen ions (however, this is not necessarily accurate at higher concentrations...

Chemical titration methods are used for analyzing acids or bases to determine the unknown concentration. A pH meter can be used to determine the point of neutralization or a pH indicator such as UI (universal indicator) which shows the point of neutralization by a distinct color change can be used. Simple stoichiometric calculations with the known volume of the unknown and the known volume and molarity of the added chemical gives the molarity of the unknown. Titration setup: the titrant drops from the burette into the analyte solution in the flask. ... In chemistry, concentration is the measure of how much of a given substance there is mixed with another substance. ... A pH meter is a specific type of voltmeter with a very high impedance of the input channels. ... A pH indicator is a halochromic chemical compound that is added in small amounts to a solution so that the pH (acidity or alkalinity) of the solution can be determined easily. ... In chemistry, stoichiometry is the study of the combination of elements in chemical reactions. ... This page refers to concentration in the chemical sense. ...

Excess gastric acid in the stomach (acid indigestion) is typically neutralized by the ingestion of sodium bicarbonate (NaHCO₃) or another neutralizing agent such as an antacid. Gastric acid is, together with several enzymes and the intrinsic factor, one of the main secretions of the stomach. ... Acid indigestion is a type of indigestion involving an excess of hydrochloric acid in the stomach. ... Sodium bicarbonate is the chemical compound with the formula NaHCO3. ... An antacid is any substance that counteracts stomach acidity. ...

Neutralization can also be used to reduce the pain of insect and plant stings. Bee stings can be neutralized with alkalis and wasps with acids. Nettle stings can be neutralised with alkalis like the one found in dock leaves.

Equal amounts (numbers of moles) of acid and base are needed for neutralization reactions between strong acids and strong bases. Use the formula: The mole (symbol: mol) is the SI base unit that measures an amount of substance. ...

a × [A] × V_a = b × [B] × V_b

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. V_a is the volume of acid and V_b is the volume of base.

See also

• Acid-base reaction theories