The amount of H₂O₂ present in 1 L of 1.5 N H₂O₂ solution is

Strength = Normality x Eq. mass

             $$\begin{gathered} = 1.5 \times 17 \left(\mathrm{eq}. \mathrm{mass} \mathrm{of} {\mathrm{H}}_2{\mathrm{O}}_2\right) \\ = 25.5 \mathrm{g} {\mathrm{L}}^{-1} \end{gathered}$$