I have recently bought what I expected to be 35 % H2O2. From a Web site, easy to find with search engines, they say that all the H2O2 they have is
less than 30 days old and kept refrigerated till they sell it.
As soon as I received it I tested it, and I am sure it is no more than 10 %.
Also, rubbed some in my thumb, slowly got a bit of the "white skin" color, light white specs. Not like good 30 % - 35 % hydrogen peroxide.
There is another Web site very similar to this one, I think probably both belong to the same person.
I strongly recomend, DON'T BUY FROM THESE GUYS. Funkerman23 - 22-6-2012 at 19:34
unless it is against forum rules knowing the seller who ripped you off could help others to avoid the same fate. Names?dann2 - 23-6-2012 at 08:13
We shall send around the 'men in boots' (the SciMad ones that is) if you don't tell us the name !!!!!!!!!
Both in the USA, they shipped from FL.Mailinmypocket - 23-6-2012 at 09:06
They even claim it is "certified"... How annoying! Titrate it and once you have a better idea of the concentration make a complaint, they even have a
phone number on their site to "speak to a "live" person".xwinorb - 23-6-2012 at 23:22
Too late to try to get a refund. I got upset and dumped it.
They sent it in a white plastice bottle, good quality container, but NO INFORMATION at all on the concentration. It has something printed like
"CONFORMS TO THE CODEX" or something like that.
I have never tried to titrate H2O2. I have read a little bit about it, and looks like you first have to prepare a permanganate solution, and then you
have to titrate your permanganate solution first, to find the concentration, then you can titrate the H2O2. Too complicated I think.
Believe me, this one is NOT at 30 %, not even close. I think I did a good estimate at 10 %, using peroxide stripes.
Usually to test a 30 % sample, I dilute it 3 : 1 with water, because the strips only test up to 10 %. This one gets the stripe black as fast as a 30 %
sample diluted to 10 %.
My advice, don't waste your time and money with them. Fossil - 24-6-2012 at 04:22
Too late to try to get a refund. I got upset and dumped it.
That seems like a terrible waste, no matter the concentration you received. You could have concentrated it yourself and saved some time since you are
starting from 10% and not 3%.
bbartlog - 24-6-2012 at 07:56
Permanganate titration wouldn't be necessary to establish the difference between 35% and 10% H2O2. I'd carefully add 10g (~100mmol) of the H2O2 to
120g of fresh household bleach solution (6.15% sodium hypochlorite, also ~100mmol). Vigorous bubbling would occur as oxygen would be immediately
released. Then I'd add a second, similar quantity of the H2O2. If it's 35%, then the first addition should exhaust the bleach and no further reaction
would occur. If it's 10%, then there should be a second round of oxygen release almost as vigorous as the first.
You could of course measure the amount of H2O2 that you had to add before bubbling stopped if you wanted to determine a rough percentage strength.
Anyway, thanks for the warning.
