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montinho
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 Posted: Sun Sep 18, 2011 8:29 pm Post subject: Oxidation of Manganese |
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Alright I am doing a lab about oxidation of manganese I need to find the products of these reactants and balance the chemical equation. This is what I have.
[b]THIS CHART[/b]
[u]Compound [/u] [u]Oxidation # of Mn[/u]
KMnO4------------------+7
K2MnO4-----------------+6
MnO2--------------------+4
MnSO4-------------------+2
MnCl3--------------------+3
1.)KMnO4+H2SO4+NaHSO3-->
2.)KMnO4+NaOH+NaHSO3-->
3.)KMnO4+NaHSO3---->
4.) KMnO4 + EDTA + MnSO4(s)---->
what role did EDTA play in this reaction? |
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montinho
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| Posted: Mon Sep 19, 2011 5:37 pm Post subject: |
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| post please! |
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expert
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| Posted: Mon Sep 19, 2011 8:29 pm Post subject: |
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Did you try it at all?
Here are some clues
1.)KMnO4+H2SO4+NaHSO3--> MnSO4, S(4+)--> S(6+)
2.)KMnO4+NaOH+NaHSO3--> K2MnO4; S(4+)--> S(6+)
3.)KMnO4+NaHSO3----> MnSO4, S(4+)--> S(6+)
4.) KMnO4 + EDTA + MnSO4(s)----> MnO2; EDTA as an acid
what role did EDTA play in this reaction?
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montinho
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| Posted: Mon Sep 19, 2011 8:44 pm Post subject: |
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k i have the following, could you please tell me if I am correct?
1) H++2KMnO4(aq)+H2SO4(aq)+5NaHSO3(aq)->2MnSO4(aq)+5K2SO4(aq)+NaSO4(aq)+3H2O
2)
2KMnO4(aq)+3NaOH(aq) + NaHSO3(aq) -> K2SO4 +2K2MnO4(aq) + 2Na2SO4(aq) + 2H2O
3)
2KMnO4 + 3NaHSO3 -> 2MnO2(s)+ K2MnO4 (aq) + 3Na2SO4(aq) + H+ + H2O |
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expert
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| Posted: Mon Sep 19, 2011 8:53 pm Post subject: |
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1) H++2KMnO4(aq)+H2SO4(aq)+5NaHSO3(aq)->2MnSO4(aq)+5K2SO4(aq)+NaSO4(aq)+3H2O
H+ already comes from H2SO4; NaSO4 incorrect: Na2SO4 correct
2)
2KMnO4(aq)+3NaOH(aq) + NaHSO3(aq) -> K2SO4 +2K2MnO4(aq) + 2Na2SO4(aq) + 2H2O
correct
3)
2KMnO4 + 3NaHSO3 -> 2MnO2(s)+ K2MnO4 (aq) + 3Na2SO4(aq) + H+ + H2O
Incorrect. K2MnO4 forms only at basic conditions. Here you generate acid. Depends on the amount of reagents the outcome is MnO2 or MnSO4 or both
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expert
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montinho
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| Posted: Mon Sep 19, 2011 8:57 pm Post subject: |
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so is 1 like this?
2KMnO4 + H2SO4 + 5NaHSO3 -> 2MnSO4 + 5K2SOR + Na2SO4 + 3H2O
??
and for 3, what should the other products be then? I know in this reaction MnO2 (s) is yielded for sure. |
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expert
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| Posted: Mon Sep 19, 2011 9:01 pm Post subject: |
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What is K2SOR?
4 KMnO4 + H2SO4 + 10 NaHSO3 = 4 MnSO4(aq) + 2 K2SO4 + 5 Na2SO4 + 6 H2O
That's it!
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Last edited by expert on Mon Sep 19, 2011 9:02 pm; edited 1 time in total |
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montinho
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| Posted: Mon Sep 19, 2011 9:02 pm Post subject: |
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[quote="expert"]What is K2SOR?[/quote]
K2SO4** |
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expert
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| Posted: Mon Sep 19, 2011 9:06 pm Post subject: |
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Incorrect
Correct is
4 KMnO4 + H2SO4 + 10 NaHSO3 = 4 MnSO4 + 2 K2SO4 + 5 Na2SO4 + 6 H2O
Use this tool if lazy http://www.webqc.org/balance.php
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montinho
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| Posted: Mon Sep 19, 2011 9:10 pm Post subject: |
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| and so what about number 3? i know one of the products is MnO2 (s), i'm sort of lost on this question. |
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expert
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| Posted: Mon Sep 19, 2011 9:15 pm Post subject: |
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Write the reaction with a single Mn-product MnO2, not MnO2 and MnSO4
If you want MnSO4 then write witha single Mn-product MnSO4
Then if you need both, add one equation to the other.
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montinho
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| Posted: Mon Sep 19, 2011 9:20 pm Post subject: |
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so is this correct?
2KMnO4 + 3NaHSO3 -> 2MnO2(s) + 3Na2SO4(aq) + H+ + H2O
?? |
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