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Suppress redox during with REACTION
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Topic: Suppress redox during with REACTION (Read 2090 times)
Flopi
Top Contributor
Posts: 26
Suppress redox during with REACTION
«
on:
December 07, 2016, 09:14:47 PM »
Hello,
I have a question on the REACTION block on redox.
I am doing the following: I have 2 solutions I am mixing, with certain quantities of ions, especially sulfate. After the mixing I need to add some sulfate. I used the REACTION keyword:
REACTION
SO4-2 0.00653
1
END
However, this causes the pH to drop significantly (from 7 to 2) and the reason seems to be the reduction of S. Is there a way to do this procedure without reducing my sulfate ? I tried to put both pe at 8 but nothing works. Is there a way to just add sulfate to the solution without the REACTION keyword ?
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dlparkhurst
Top Contributor
Posts: 3174
Re: Suppress redox during with REACTION
«
Reply #1 on:
December 07, 2016, 10:26:06 PM »
You should not add a charged species; in fact, REACTION ignores the charge that you put in.
Add a charge balanced reaction, like Na2SO4, and your redox reaction will go away. Essentially you added SO4, which reacted SO4 + H2O = SO4-2 + 2H+ + 0.5O2
REACTION
Na2SO4 0.00653
1
END
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Flopi
Top Contributor
Posts: 26
Re: Suppress redox during with REACTION
«
Reply #2 on:
December 07, 2016, 10:49:00 PM »
Thanks a lot for the answer !
(I thought previously that it didn't solve the problem, but because I put NaSO4 instead of Na2SO4...) Now everything works perfectly
«
Last Edit: December 07, 2016, 11:01:50 PM by Flopi
»
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Suppress redox during with REACTION