Hi Borek, and thanks for that, it is much appreciated.
I had come up with something a little different following what I thought was logic. Maybe someone could point out the flaws
, bearing in mind it could be quite fundamental!
Working on the following info from http://www.unc.edu/~rowlett/units/dictW.html
an abbreviation for "by weight," used in chemistry and pharmacology to describe the concentration of a substance in a mixture or solution. Properly speaking, 2% w/w means that the mass of the substance is 2% of the total mass of the solution or mixture. The metric symbol g/g has the same meaning as w/w.
I went ahead and calculated the total mass of H2O2 required for 1l -
m1 = (0.2)(density)(vol) - 0.2(1070kg/m3)(0.001m3) = 0.214kg
So how much 30% H2O2 do I need to have this mass and then top up to 1l using H2O
0.214 = (0.3)(1.1)(V) - V = 0.713m3 or 713ml
Thanks again for the help folks.