To prepare a 100 mL solution of 0.1 M H2O2, one needs to calculate the number of moles required, which is 0.01 moles. This translates to a mass of 0.34 grams of hydrogen peroxide, based on its molar mass of 34 g/mol. However, the discussion highlights that the specific concentration of the hydrogen peroxide solution available is crucial for accurately preparing the solution. Without knowing the concentration of the starting material, providing a precise recipe is challenging. The mass calculation is confirmed, but additional context on the source of H2O2 is necessary for complete guidance.