A reaction in which an acid and a base react to produce a salt and water

When an acid and a base are placed together, they react to neutralize the acid and base properties, producing a salt. The H(+) cation of the acid combines with the OH(-) anion of the base to form water. The compound formed by the cation of the base and the anion of the acid is called a salt. The combination of hydrochloric acid and sodium hydroxide produces common table salt, NaCl:

A reaction in which an acid and a base react to produce a salt and water

The word salt is a general term which applies to the products of all such acid-base reactions.


Periodic Table

Acid concepts

Chemical reaction concepts

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  • Page ID47560
  • Learning Objectives
    • Write acid-base neutralization reactions.
    • Write reactions of acids with metals.
    • Write reactions of bases with metals.

    Neutralization Reactions

    The reaction that happens when an acid, such as \(\ce{HCl}\), is mixed with a base, such as \(\ce{NaOH}\):

    \[\ce{HCl (aq) + NaOH (aq) → NaCl (aq) + H_2O (l)}\nonumber \]

    When an acid and a base are combined, water and a salt are the products. Salts are ionic compounds containing a positive ion other than \(\ce{H^{+}}\) and a negative ion other than the hydroxide ion, \(\ce{OH^{-}}\). Double displacement reactions of this type are called neutralization reactions. We can write an expanded version of this equation, with aqueous substances written in their longer form:

    \[\ce{H^{+} (aq) + Cl^{-} (aq) + Na^{+} (aq) + OH^{-} (aq) → Na^{+} (aq) + Cl^{-} (aq) + H_2O (l)}\nonumber \]

    After removing the spectator ions, we get the net ionic equation:

    \[\ce{H^{+} (aq) + OH^{-} (aq) → H_2O (l)}\nonumber \]

    When a strong acid and a strong base are combined in the proper amounts—when \([\ce{H^{+}}]\) equals \([\ce{OH^{-}}\)]\)—a neutral solution results in which pH = 7. The acid and base have neutralized each other, and the acidic and basic properties are no longer present.

    Salt solutions do not always have a pH of 7, however. Through a process known as hydrolysis, the ions produced when an acid and base combine may react with the water molecules to produce a solution that is slightly acidic or basic. As a general concept, if a strong acid is mixed with a weak base, the resulting solution will be slightly acidic. If a strong base is mixed with a weak acid, the solution will be slightly basic.

    Video: Equimolar (~0.01 M) and equivolume solutions of \(\ce{HCl}\) and \(\ce{NaOH}\) are combined to make salt water. https://youtu.be/TS-I9KrUjB0

    Example \(\PageIndex{1}\): Propionic Acid + Calcium Hydroxide

    Calcium propionate is used to inhibit the growth of molds in foods, tobacco, and some medicines. Write a balanced chemical equation for the reaction of aqueous propionic acid (CH3CH2CO2H) with aqueous calcium hydroxide [Ca(OH)2].

    Solution Solutions to Example 14.5.1


    Write the unbalanced equation.

    This is a double displacement reaction, so the cations and anions swap to create the water and the salt.

    CH3CH2CO2H(aq) + Ca(OH)2(aq)→(CH3CH2CO2)2Ca(aq) + H2O(l)

    Balance the equation.

    Because there are two OH− ions in the formula for Ca(OH)2, we need two moles of propionic acid, CH3CH2CO2H, to provide H+ ions.

    2CH3CH2CO2H(aq) + Ca(OH)2(aq)→(CH3CH2CO2)2Ca(aq) +2H2O(l)

    Exercise \(\PageIndex{1}\)

    Write a balanced chemical equation for the reaction of solid barium hydroxide with dilute acetic acid.


    \[\ce{Ba(OH)2(s) + 2CH3CO2H (aq)→Ba(CH3CO2)2 (aq) + 2H2O(l)} \nonumber \nonumber \]

    Acids and Bases React with Metals

    Acids react with most metals to form a salt and hydrogen gas. As discussed previously, metals that are more active than acids can undergo a single displacement reaction. For example, zinc metal reacts with hydrochloric acid, producing zinc chloride and hydrogen gas.

    \[\ce{Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)}\nonumber \]

    Bases also react with certain metals, like zinc or aluminum, to produce hydrogen gas. For example, sodium hydroxide reacts with zinc and water to form sodium zincate and hydrogen gas.

    \[\ce{Zn(s) + 2NaOH (aq) + 2H2O(l) → Na2Zn(OH)4(aq) + H2 (g)}.\nonumber \]

    Acid + base = salt + water

    When acids react with bases, they produce a salt and water.

    A reaction in which an acid and a base react to produce a salt and water

    When a seed (acid) played her bass (base) drum she became very upset and began to cry salty tears (salt + water). 

    This is an example of a neutralisation reaction, as the acid and base neutralise each other.

    More Info

    What is the reaction of an acid and base to produce salt and water?

    Neutralization reaction is a chemical reaction in which an acid and a base interact with the formation of a salt with strong acids and bases the essential reaction is the combination of hydrogen ions with hydroxyl ions to form water. Was this answer helpful?

    What reaction produces a salt and water?

    When acid and base solutions react, they produce water and a neutral ionic compound called a salt. The reaction is called a neutralization reaction.

    What type of chemical reaction is acid base water salt?

    Since this is a neutralization reaction, the two products will be water and a salt composed of the cation of the ionic hydroxide (Ba2+) and the anion generated when the acid transfers its hydrogen ion (NO−3). Write the net ionic equation representing the neutralization of any strong acid with an ionic hydroxide.