Final answer:
The anion in the aqueous solution of Cu(C2H3O2)2 is the acetate ion, with the chemical formula C2H3O2−.
Step-by-step explanation:
The chemical formula for the anion present in the aqueous solution of Cu(C2H3O2)2 is C2H3O2−. This is the acetate ion, which is a common anion in many compounds and solutions. When copper(II) acetate is dissolved in water, it dissociates into Cu2+ ions and acetate ions. Since the ionic compound must be electrically neutral, two acetate ions are associated with each copper ion to balance the charge, as indicated by the subscript '2' in the formula of copper(II) acetate.