Chapter 16, Problem 16.54SP

Aqueous solutions of hydrogen sulfide contain ${\text{H}}_{\text{2}}{\text{S,HS}}^{\text{-}}\text{,}$ ${\text{S}}^{\text{2-}},$ $H_3{O}^{+}$ , ${\text{OH}}^{\text{-}},$ and ${\text{H}}_{\text{2}}{\text{O}}^{\text{-}}$ in varying concentrations. Which of these species can act only as an acid? Which can act only as a base? Which can act both as an acid and as a base?