Question

How does Arrhenius describe acids and bases?

Answer 1

As defined by Arrhenius:

An Arrhenius acid is a substance that dissociates in water to form hydrogen ions (H+). In other words, an acid increases the concentration of H+ ions in an aqueous solution. This protonation of water yields the hydronium ion (H3O+); in modern times, H+ is used as a shorthand for H3O+ because it is now known that a bare proton (H+) does not exist as a free species in aqueous solution.

An Arrhenius base is a substance that dissociates in water to form hydroxide (OH–) ions. In other words, a base increases the concentration of OH– ions in an aqueous solution.

Hope this helps!

Answer 2

Explanation:

According to Arrhenius concept:

An acid is defined as a substance which donates hydronium ions $(H_3O^+)$ in water.

$HA(aq)+H_2O(l)\rightarrow A^-(aq)+H_3O^+(aq)$

For example: hydrochloric acid , nitric acid etc.

$HCl(aq)+H_2O(l)\rightarrow Cl^-(aq)+H_3O^+(aq)$

$HNO_3(aq)+H_2O(l)\rightarrow NO_3^{-}(aq)+H_3O^+(aq)$

A base is defined as a substance which donates hydroxide ions $(OH^-)$ when dissolved in water.

$BOH(aq)\rightarrow B^+(aq)+OH^-(aq)$

For example: sodium hydroxide, calcium hydroxide etc.

$NaOH(aq)\rightarrow Na^+(aq)+OH^-(aq)$

$Ca(OH)_2(aq)\rightarrow Ca^{2+}(aq)+2OH^-(aq)$