Question

Be sure to answer all parts. The active agent in many hair bleaches is hydrogen peroxide. The amount of H2O2 in 14.5−g of hair bleach was determined by titration with a standard potassium permanganate solution: 2 MnO4−(aq) + 5 H2O2(aq) + 6 H+(aq) → 5 O2(g) + 2 Mn2+(aq) + 8 H2O(l) (a) For the titration, how many moles of MnO4− were required if 40.8 mL of 0.154 M KMnO4 was needed to reach the end point? Write your answer to the correct number of significant figures. Enter your answer in scientific notation. ______ × 10 mol MnO4− (b) How many moles of H2O2 were present in the 14.5 g sample of bleach? Write your answer to the correct number of significant figures. ____ mol H2O2