From: Randall Webb (randall.webb@lineone.net)
Date: 03/02/01-01:23:43 AM Z
----- Original Message -----
From: <alnovo@inwind.it>
To: <alt-photo-process-l@skyway.usask.ca>
Sent: Thursday, March 01, 2001 12:01 AM
Subject: Re: Hydrogen Peroxide Warning
> > I find this discussion on peroxide both alarming and confusing. 35%
seems a
> > little extreme and potentially dangerous. We buy peroxide from
pharmacies
> > here at either 20 or 30 vols which I assume means 2 or 3%.
> > Randall Webb
> >
>
> the concentration of H2O2 in vols means: "volumes of O2 (oxygen) that 1
vol of solution of H2O2 can liberate from its decomposition".
> So, a 10% H2O2 is about 100/34 (mol. weight of H2O2) = about 1.47 moles of
H2O2 in 1 dm3 of solution. Every mole of H2O2, decomposing, yelds 1 mole of
H2O and 1/2 mole of O2. As 1 mole of perfect gas, at 273 Kelvin degrees (0
centigrades) and at sea level pressure, has a volume of 22.4 dm3, 1.5 moles
of O2 will have a volume of 1.47*22.4 = 32.9 dm3.
>
> The ratio between % and vols is then 3.3. A 20 and 30 vols solutions are
respectively equivalent to 6.6 and 9.9%
>
> Alberto>>>>>>>>>>>
Many thanks for the clarification. Its just that I have this feeling that
I shouln't really have got involved in this sort of
discussion!!!!!!!!!!!!!!!
Randall Webb
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