The question is incomplete, the complete question is shown in the image attached.
Answer:
7.69%
Explanation:
The balanced equation of this reaction is shown in the image attached to this answer.
The reaction is redox because we can notice a change in the oxidation number of species from left to right in the reaction equation.
For instance, the oxidation number of oxygen was changed from -1 in H2O2 to zero in O2. Hence H2O2 was oxidized.
To calculate the percentage of H2O2 in the sample;
number of moles of KMnO4 = 137 ml/1000 * 0.230 M = 0.03151 moles of KMnO4
From the reaction equation;
2 moles of permanganate reacts with 5 moles of H2O2
0.03151 moles of permanganate reacts with 0.03151 moles * 5/2 = 0.079 moles of H202
Mass of H2O2 reacted = 0.079 moles of H202 * 34 gmol-1 = 2.69 g
Hence % by mass of H2O2 in the sample = 2.69 g/35 g * 100 = 7.69%