[karlkem]

I think I stumbled upon a way to make sulfuric acid at home using sodium thiosulfate and hydrogen peroxide.

I say stumbled because I had no intention to make sulfuric acid at all. The experiment I did was extraction of elemental iodine from tincture of iodine, HCL (31.45%, 10.3 M) and H202 (3%). After filtering and evaporating the crystals, I then neutralized the free iodine ions from the filtrand using sodium thiosulfate (the solution turned a cloudy yellow and a yellow precipitate formed on the bottom (S2). I found out that a side reaction of the thiosulfate and H202 is sulfuric acid:
Na2S2O3 + 4H2O2(aq) → Na2SO4(aq) + H2SO4(aq) + 3H2O(I)

I'm not sure how much H2O2 was left over from the reaction with HCL and tincure of iodine, but I put a strip of universal pH indicator paper in the cloudy yellow liquid and the strip turned a deep red, indicating a highly acidic solution. I also previously wafted with  my hand a bit towards me to get a sniff...and I sensed it as extremely pungent...and corrosive to nasal passages.

However, I'm still not full well sure that I obtained sulfuric acid..It is merely an educated guess I derived from researching around the web. Thought I'd ask here to see if anyone has more experience with this reaction or could tell me if the liquid I made contains sulfuric acid or not.

Thanks in advance!

Karlkem

[karlkem]

  :(Perhaps I didn't express myself clearly. Basically what I was wondering was if
I mixed sodium thiosulfate with hydrogen peroxide, you get sulfuric acid as one of the products.

[AWK]

Answer with details is here.
Look at the reactions, plots and  an abstract at the end of paper.

[karlkem]

Answer with details is here.
Look at the reactions, plots and  an abstract at the end of paper.

I don't see the answer you are referring to. Am I missing something?
Which paper are you talking about? Link?

Nevertheless, I'm grateful for your response.

[AWK]

http://www.google.pl/search?client=opera&rls=pl&q=NA2s2O3+H2O2&sourceid=opera&ie=utf-8&oe=utf-8

Sorry, link disappeared

[karlkem]

http://www.google.pl/search?client=opera&rls=pl&q=NA2s2O3+H2O2&sourceid=opera&ie=utf-8&oe=utf-8

Sorry, link disappeared

Thanks. Did you ever perform this reaction yourself? If not,
how did you know what the product of NA2s2O3 + H2O2 was going to be?
I wonder what chemists did before google to find out the products of
any given reactants. I guess they only had experimentation.

Sorry for the beginner questions. I understand how to balance equations
fairly well. What I find difficult sometimes is how to predict what the
products of a reaction will be. It seems like you either have to see for
yourself by performing the reaction, or check google.

I have not studied the periodic table to any great extent. I think the answer
to how to predict any reaction products must lie there.

I'd appreciate hearing what you've got to say about this challenge for a beginner
of finding out the products of any given reactants.

[AWK]

The first google link: ([PDF] H2O2'Na2S2O3 反应对pH 和反应物起始浓度比的依8性)
==> http://www.whxb.pku.edu.cn/CN/article/downloadArticleFile.do?attachType=PDF&id=25345

The reference show you kinetic measurements of this reaction. On page 774 you can see plots of different experiments. With 4:1 molar ratio (H2O2 to thiosulfate), practically sulfate is the only product (Fig. 1g) at all pH. When H2O2 is a limiting reagent the reaction is hardly pH dependent (Fig. 1a,c,e). Table 1 on page 773 list all possible equilibria taken into accounts in this work.