Final answer:
In the aqueous phase, most of the organic acid exists in the nonionized molecular form, with a smaller portion existing as dissociated ions.
Step-by-step explanation:
When an organic acid is extracted into the aqueous phase, it predominantly exists in a nonionized or molecular form, especially if it is a weak acid like acetic acid or benzoic acid. In the aqueous solution, a small fraction of the organic acid dissociates into ions, but the majority remains in the hydrated molecular form. For example, benzoic acid in the aqueous solution at a pH of 2.85 has approximately 95% in the molecular form, C6H5CO2H(aq), and only about 5% as dissociated ions. This is due to the establishment of an equilibrium in the solution, where most of the carboxylic acid is in the nonionized form. However, when considering the solubility of carboxylic acids, those with shorter carbon chains tend to be very soluble in water, contributing to the presence of more acid in the aqueous phase.