# Are hydronium ions contributed to a solution by an acid or a base?

Aug 1, 2017

Brønsted-Lowry and Arrhenius *acids* introduce ${\text{H}}^{+}$ in solution.

#### Explanation:

In the Arrhenius acid definition, the acid introduces ${\text{H}}^{+}$ (i.e. ${\text{H"_3"O}}^{+}$) into the solution, because the polarity of the water molecule solvated the hydrogen from the molecule.

Here, $\text{HCl}$ acts as the Arrhenius acid (as well as the Brønsted-Lowry acid, as discussed below:)

In the Brønsted-Lowry acid definition, the acid donates an ${\text{H}}^{+}$ (a proton) to a base to form the acid's conjugate base (the base becomes its conjugate acid):

In this image, $\text{H"_2"O}$ acts as the Brønsted-Lowry acid, and ${\text{NH}}_{3}$ acts as the Brønsted Lowry base.

Acids in the Arrhenius and Brønsted-Lowry definitions are quite similar; essentially, both definitions require for the acid to dissociate into ${\text{H}}^{+}$, only the Brønsted-Lowry definition requires that it be donated to a base in solution.