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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: Jabean on September 22, 2012, 09:38:38 AM

Title: Redoxreaction of hydrogen peroxide and thiosulfate ions in acidic solution
Post by: Jabean on September 22, 2012, 09:38:38 AM
Hi,
I have a redox reaction which looks like the following:
(http://i.imgur.com/pZpYA.png)
In an acidic solution. I tried balancing this myself and reached the following:
(http://i.imgur.com/W50FD.png)
However, I was told this was wrong. Can anyone shed some light on this, and if it is wrong, explain where and how to fix it?

Thanks in advance!
Title: Re: Redoxreaction of hydrogen peroxide and thiosulfate ions in acidic solution
Post by: Borek on September 22, 2012, 10:14:09 AM
Not sure what LHO means, and what is the meaning of the arrows you have drawn, but the reaction is correctly balanced.
Title: Re: Redoxreaction of hydrogen peroxide and thiosulfate ions in acidic solution
Post by: Jabean on September 22, 2012, 10:23:18 AM
LHO is basically charge, hydrogen count, and oxygen count. We use them for adding H+ and water and checking our answer. The arrows are reductions and oxidations, and that is what was wrong. After some devising, this is the final balancing:
(http://i.imgur.com/ayXzP.png)
Which still gives the same result but some different reductions/oxidations.

Thanks for the confirmation!
Title: Re: Redoxreaction of hydrogen peroxide and thiosulfate ions in acidic solution
Post by: Vargouille on September 23, 2012, 10:24:45 AM
Your balancing is correct, but not the arrows.

Remember your half-reactions:

H2O2 + 2H+ + 2e- :rarrow: 2H2O
2S2O32- :rarrow: S4O62- + 2e-