Other than water, which species would you expect to find in the highest concentration in an aqueous solution of \(\mathrm{CH}_{3} \mathrm{COOH}\) ? Explain.

Acetic acid (CH3COOH) is a weak acid, which means it partially dissociates in water. The dissociation equation of acetic acid in water is given by: \(\mathrm{CH}_{3} \mathrm{COOH} + \mathrm{H}_{2}\mathrm{O} \rightleftharpoons \mathrm{CH}_{3} \mathrm{COO}^{-} + \mathrm{H}_{3}\mathrm{O}^{+}\) Here, CH3COOH dissociates into the acetate ion (CH3COO-) and the hydronium ion (H3O+).

From the dissociation of acetic acid in water, we can determine the main species present in the solution: 1. water (H2O) 2. acetic acid (CH3COOH) 3. acetate ions (CH3COO-) 4. hydronium ions (H3O+) Since water (H2O) is not considered in this exercise, we will focus on the other three species.

As acetic acid is a weak acid, most of the acetic acid molecules will remain undissociated in the aqueous solution, with only a small fraction dissociating into the acetate ions and hydronium ions. This means that the concentration of undissociated acetic acid molecules will be higher than the concentrations of the acetate and hydronium ions. Since the dissociation of acetic acid in water is an equilibrium process, the concentrations of acetate and hydronium ions will be equal. Comparing the concentrations of the three species in the solution (other than water): 1. acetic acid (CH3COOH) - highest concentration 2. acetate ions (CH3COO-) - lower concentration than CH3COOH 3. hydronium ions (H3O+) - lower concentration than CH3COOH

Based on the analysis above, we can conclude that other than water, the species with the highest concentration in an aqueous solution of acetic acid (CH3COOH) is the undissociated acetic acid molecules (CH3COOH).