[Whapper2006]

Density of H2O2: 1.01 g/mL
% Composition H2O2: 3.1 %
Volume of H2O2 used: 5.0 mL

what i did was write out
2H20 + 02 -> 2H202

so its 1:2 moles ratio. The density of H202 is 1.01g/ml. there are 5 ml of it so there are 5.05 grams. The moles of H202 is .148 moles. Since its a 1:2 ratio the moles of 02 should be .074?

But wat about the 3.1% composition of H202, do I have to do anything with that?

[Arkcon]

But wat about the 3.1% composition of H202, do I have to do anything with that?

Oh yes.