Arrhenius acid-base theory

Written by J.A Dobado | Last Updated on April 22, 2024

What is the Arrhenius acid-base theory?

Acids: substances that in aqueous solution dissociate by yielding protons (H+).

  • Acids: sustancias que en disolución acuosa se disocian cediendo protones (H+).
  • Bases: substances that in aqueous solution dissociate by yielding hydroxide ions (OH).
  • Salts: substances that in aqueous solution dissociate by yielding other ions.

In general the dissociation equations are:

Acid: AH -> A + H+

NaOH -> Na+ + OH


HNO3 -> NO3 + H+ (monoprotic acid)

H2SO4 -> SO42- + 2H+ (diprotic acid)

H3PO4 -> PO43- + 3H+ (triprotic acid)

NaOH -> Na+ + OH

Ca(OH)2 -> Ca2+ + 2OH

Neutralization process

The neutralization process consists of the reaction of an acid and a base to give a salt and water.

H+ + OH -> H2O

In short, it can be written in general terms

H+ + OH -> H2O

So all the properties of the neutralization reaction must be the same for any acid and any base.

For example: the heat of neutralization is the same regardless of the acid and base used in the neutralization.

Video about Arrhenius definition of acids and bases


What is an Arrhenius acid and base?

The Arrhenius theory of acids and bases was originally proposed by the Swedish chemist Svante Arrhenius in 1884, who suggested classifying certain compounds as acids or bases according to the type of ions formed when the compound is added to water.

What does Arrhenius’ law say?

The Arrhenius equation is k = Ae^(-Ea/RT), where A is the frequency or pre-exponential factor and e^(-Ea/RT) represents the fraction of collisions that have sufficient energy to overcome the activation barrier (i.e., have greater than or equal to the activation energy Ea) at temperature T.