Final answer:
In acid solutions, hydronium ions (H3O+) are present due to the ionization of acids. Carbonated water is one example of an acid solution where carbonic acid ionizes to produce H3O+, HCO3−, and CO32−, and their concentrations depend on the initial concentration of the acid.
Step-by-step explanation:
Acid solutions contain hydronium ions (H3O+) which result from the ionization of acids in water. For example, carbonic acid (H2CO3) will ionize in water to produce H3O+, hydrogen carbonate ion (HCO3−), and carbonate ion (CO32−). The initial concentration of carbonic acid affects the concentrations of these ions. In a saturated solution of carbon dioxide with an initial [H2CO3] = 0.033 M, one would determine the [H3O+], [HCO3−], and [CO32−] by taking into account the acidic constants (Ka's) of carbonic acid and applying principles such as Le Châtelier's principle, which explains how the water autoionization equilibrium shifts under the stress of increased hydronium ion concentration.