The following oxidation-reduction reaction occurs in acidic solution. When the equation is balanced using the smallest set of whole-number stoichiometric coefficients possible, what is the stoichiometric coefficient for water? (Hint: In addition to the species shown in the original equation, H⁺(aq) and H₂O(l) can also appear in the balanced equation.)
MnO₄⁻(aq) + HOCH₂CH₂OH(aq) → Mn₂+(aq) + HO₂C-CO₂H(aq)