Reaction of Hydrogen Peroxide with Potassium Permanganate

1. For the NEW bottle of hydrogen peroxide, record and calculate the following:

(a) Initial burette reading of potassium permanganate used in each titration (mL) and concentration:

(b) The volume of potassium permanganate required to titrate each 10.00 mL portion of the new hydrogen peroxide (mL): (record all three trials' data)

(c) Calculate the number of moles of the H2O2 in the 10.00 mL sample in every titration from the volume of KMnO4 used and the stoichiometry of the reaction.

(d) Take the average of the two closest values you found in step (c).

(e) Use the average from step (d) to calculate the molarity of the H2O2.

(f) Calculate the % by mass (mass) of H2O2 in the original sample. Assume the density is 1.00 g/mL for the NEW H2O2. (MW of H2O2 is 34.01 amu)

2. Repeat the calculations for the OLD bottle of H2O2:

(a) Initial burette reading of potassium permanganate used in each titration (mL) and concentration:

(b) The volume of potassium permanganate required to titrate each 10.00 mL portion of the old hydrogen peroxide (mL):(record all three trials's data)

(c) Calculate the number of moles of the H2O2 in the 10.00 mL sample in every titration from the volume of KMnO4 used and the stoichiometry of the reaction.

(d) Take the average of the two closest values you found in step (c).

(e) Use the average from step (d) to calculate the molarity of the H₂O₂.

(f) Calculate the % by mass of H2O2 in the original sample. Assume the density is 1.00 g/mL for the OLD H2O2.(MW of H2O2 is 34.01 amu)

3. Commercial hydrogen peroxide contains small amounts of organic compounds that are added to stabilize it. If these compounds react with permanganate, how would this affect your results in terms of the % by mass of H2O2?

my data was: KMnO4 added to new peroxide: 20ml to reach the end point
18.1ml
18.05ml
KMnO4 added to old peroxide: 16ml to reach end point
molarity for KMnO4 is .2M 13ml to reach end point
12.65ml to reach end point

the chemical reaction given to use for calculation is:
2[MnO4-]aq + 6[H+]aq + 5[H2O2]aq ---> 5[O2]g + 2[Mn(2+)]aq + 8[H2O]l

Solution Summary

Using lab data, this solution explains:

1) How to calculate the number of moles of H2O2 titrated during in a titration using KMnO4.

2) How to use this data to calculate the molarity of the H2O2.