Re: h2o2 35% food ???

farooq_w_at_hotmail.com
Date: 01/30/05 

Date: 30 Jan 2005 11:29:14 -0800

wsb wrote:
> hi
>
> Many online stores offer H2O2 food grade 35% but just to be sure,
does
> this means it is 120 Vol (+ or -).
>
> thanks
>
> wasban

Yes it is, 35% is around 120 volumes. What do you mean by + or -?
Instead of asking you can learn this conversion. I will give you an
example of converting 10 vol H2O2 to its percentage, you can do it
yourself then.

2H202 ------> 2H20 + O2
2 x 34.02 g 22.4 L (STP)

Suppose 1 L of H202 decomposes to give 10 L of oxygen.

Moles of oxygen 10 /22.4 = 0.446 mol ( Molar volume at 0 oC ­= 22.4 L)

Moles of peroxide = 0.446 mol x 2 = 0.893 mol

Mass of H202 = 0.893 x 34.02 = 30. 37 g
% w/vol H202 = 30.37g/1000 * 100 = 3.03 %