Question

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

Answer 1

Brønsted-Lowry and Arrhenius *acids* introduce `"H"^+` in solution.

Explanation:

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

Here, `"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 `"H"^+` (a proton) to a base to form the acid's conjugate base (the base becomes its conjugate acid):

In this image, `"H"_2"O"` acts as the Brønsted-Lowry acid, and `"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 `"H"^+`, only the Brønsted-Lowry definition requires that it be donated to a base in solution.