Calculate the strength of 5 volume H2O2 solution.
The molar mass of H2O2 is 34gm. According to this reaction, 2 moles of peroxide is involved, so mass becomes 68gm.
we know that 1mole of any gas occupies a volume of 22.4L at NTP.
Now, 5 volume H2O2 solution means that 1 L of 5 volume H2O2 on decomposition gives 5L of O2 at NTP.
5L of O2 at NTP, we need (68/22.4*5 ) gm H2O2
Strength of H2O2 in 5 volumes of it is 15.179gm/L