CHM1 20Example3 Collection

Solution At the equivalence point, the stoichiometric ratio will apply, and we can use it to calculate the amount of KMnO₄ which must be added:

The amount of H₂O₂ is obtained from the volume and concentration:

Then


= 1.272mmol KMnO₄
To obtain V_KMnO4(aq) we use the concentration as a conversion factor:

= 23.62 cm³
Note that overtitrating [adding more than 23.62 cm³ of KMnO₄(aq) would involve an excess (more than 1.272 mmol) of KMnO₄.