4, experimental procedure 1) Preparation of KMnO4 solution (0.02 mol · dm-3), said KMnO4 take about 1.7g beaker, add water 500cm3, after it dissolved into a brown reagent bottle. Place 7-10 days, filtered through a glass frit funnel. The residue and precipitation are drained. Wash reagent bottle, and the filtrate back into the bottle, to be calibrated. 2) Calibration KMnO4 solution Weigh 0.15 ~ 0.20g previously dried Na2C2O4 three were placed 250cm3 conical flask, distilled water and added to each 40cm3 10cm33 mol · dm-3 H2SO4, heated on a water bath about 75 straight 85 ℃. Serve hot with KMnO4 solution was titrated to be calibrated, at the beginning, Henan agent hydrogen peroxide, titration rate should slow, after the first drops of KMnO4 solution was dropped, and constantly shaken solution, when the purple recede after second drop instillation. There Mn2 + solution after generation, the titration may be appropriate to speed up the pace, near the end, the use of hydrogen peroxide, purple faded very slowly, titration rate should slow down, while fully shake the solution. When the solution presented reddish and does not fade in half a minute, is the end. Calculate the concentration of KMnO4 solution. Titration to maintain a temperature of not lower than 60 ℃. 3) Determination of H2O2 content: using pipette sample 5.00cm3 hydrogen peroxide (H2O2 content of about 5%), where the sale of hydrogen peroxide, placed 250cm3 flask, dilute to the mark with water, mix well. Draw 25cm3 of the diluted liquid three, hydrogen peroxide, were placed in three 250cm3 conical flask, each added 5cm33 mol · dm-3 H2SO4, KMnO4 standard titration purposes. H2O2 content of the sample is calculated. Impurity is an important factor affecting the stability of hydrogen peroxide. Many of divalent metal ions such as iron ions, divalent manganese ions, cupric ions, trivalent chromium ions will promote the decomposition of hydrogen peroxide. Since the industrial composition contains a large amount of metal ions of hydrogen peroxide and the like substances, so, in the industrial-grade hydrogen peroxide production process, usually by adding a large amount of stabilizer in hydrogen peroxide to suppress catalytic impurities. Hydrogen peroxide Sellers | Hydrogen peroxide | Zhengzhou Longda Chemical (Views) provided by the Zhengzhou Longda Chemical Products Limited. Road Zhiyuan, temper forward. Zhengzhou Longda Chemical Products Co., Ltd. (www.longdahuagong.com/) aims to become and you win symbiosis, strategic partners to move forward, more determined to become the most influential of inorganic acid companies, and you leap together to success !