The oxidation of ethanedioate ions by acidified manganate(VII) ions proceeds very slowly at room temperature. $2\text{MnO}_4^- + 5\text{C}_2\text{O}_4^{2-} + 16\text{H}^+ \rightarrow 2\text{Mn}^{2+} + 10\text{CO}_2 + 8\text{H}_2\text{O}$ $\text{Mn}^{2+}$ ions act as catalysts for this reaction. Which graph shows the way the concentration of acidified manganate(VII) ions changes after ethanedioate ions are added?
Chemistry 9701 · AS & A Level · Reaction kinetics