Redox titrations are used to determine the amounts of oxidizing and reducing agents in solution. for example, a solution of hydrogen peroxide, h2o2, can be titrated against a solution of potassium permanganate, kmno4. the following equation represents the reaction: 2kmno4(aq) h2o2(aq) 3h2so4(aq)→3o2(g) 2mnso4(aq) k2so4(aq) 4h2o(l) a certain amount of hydrogen peroxide was dissolved in 100. ml of water and then titrated with 1.68 m kmno4. what mass of h2o2 was dissolved if the titration required 20.8 ml of the kmno4 solution

0.595 g of H₂O₂ were dissolved.

Explanation:

1) Balanced chemical equation of the titration (given):

                                                → 3O₂(g) + 2MnSO₄(aq)+  K₂SO₄(aq) + 4H₂O(l)

2) Mole ratios of KMnO₄(aq) and H₂O₂(aq) (the reactants the question deals with):

3) Number of moles of KMnO₄ used:

4) Number of moles of H₂O₂ used:

       2 moles KMnO₄ / 1 mol H₂O₂ = 0.0349 moles KMnO₄ / x

       ⇒ x = 0.0349 / 2 moles H₂O₂ = 0.0175 moles H₂O₂

5) Mass of H₂O₂ dissolved:

So, the answer, using the appropiate number of signficant digits (3) is 0.595 g of H₂O₂.

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