The first issue arose when standardizing Hydrogen Peroxide with Potassium Permanganate. Potassium Permanganate tends to deteriorate after long periods of time . During the first titration of hydrogen peroxide, an unexpectedly large amount of KMnO₄ was needed to completely react with the peroxide. This can be explained by the deterioration of KMnO₄ and the resulting decrease in the concentration of the Potassium Permanganate solution over time. Thus, a new KMnO₄ solution was prepared and standardized with oxalic acid.