Re: What does 100vol w/v mean on a bottle of hydrogen peroxide?

Hi,

Sorry it took me so long to get back to you about this question, but the 
answer was quite challenging to track down.  I asked many professors here 
at Washington University and several chemists I know, and no one knew the 
answer.  The Merck index, in addition, was not at all helpful.  The answer 
can be found in "Principles of Quantitative Inorganic Analysis" by A.I. 
Vogel, published in 1939 (!).  "Hydrogen peroxide is marketed in four 
concentrations, "10", "20", "40" and "100 volume" concentrations.  The "10 
volume" solution refers to the fact that the solution when fully decomposed 
by heat, yields 10 times its volume of oxygen measured at 0 C. and 760 mm."  
So basically, 1 liter of a 30% solution will generate 100 liters of O2 when 
decomposed.  H2O2 is always calculated weight/volume (w/v) probably because 
of the way it is analyzed.  

So your bottle, since it says 100vol would be a 30% solution.  Now that you 
have that information, you could then calculate the molarity, given that 
the molecular weight is 34.

Good luck.

Julianne Dunphy