H2O2 in Bleach - How much Hydrogen Peroxide is in Bleach...

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How much Hydrogen Peroxide is in Bleach? Group 2: TA: Seunghyun CHM 116 L18(70667) W 2:30 pm - 4:20 pm, PSH-136 Introduction This lab focused on the on the process of redox reactions. In a reduction-oxidation reaction one substance gains an electron while another loses one. The molecule or atom that loses the electron is said to be oxidized, while the one that gains the electron is reduced. This lab utilizes
a technique called titration in which a solution with a known concentration is slowly added to a solution of unknown concentration until the solution is neutralized. The neutralization is indicated by a change in color of the titrated solution. Through titration we can find the exact molarity of a solution. This is called standardization and it is important in a plethora of calculations. In order to do any calculation that deals with concentration, we must standardize. In this lab, we will first seek to standardize a solution of potassium permanganate using solid samples of FAS (iron(II) ammonium sulfate hexahydrate) via titration. The chemical reaction for this is: MnO 4 - (aq) + 5 Fe 2+ (aq) + 8 H + (aq) → Mn 2+ (aq) + 5 Fe 3+ (aq) + 4 H 2 O (l). Then once the molarity of KMnO 4 is found, we will use that to calculate the mass percentage of hydrogen peroxide in bleach by titration once again. The final reaction is: 2MnO 4 - (aq) + 5 H 2 O 2 (aq) + 6H + (aq) → 2 Mn 2+ (aq) + 5O 2 (g) + 8H 2 O(l). Methods Experiment 1: The buret for the experiment was initially rinsed out with boiled distilled water three times to make sure that there was no residue left from previous experiments. Then the buret was primed by having KMnO 4 run through the entire volume of the buret twice. For trial one, 0.251 grams of FAS was measured out and placed in 250 mL beaker. 2.0 mL of H 2 SO 4 was mixed into the beaker along with 10 mL of boiled distilled water. Then two drops of H 3 PO 4 was added. The contents were then stirred till the entire contents seemed to be dissolved. The H 2 SO 4 was of a 9 molar concentration and the H 3 PO 4 was of a 6 molar concentration. KMnO 4 was then added via

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