oxidation state of MnO4-

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Joanna Pham - 2D
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Joined: Fri Apr 06, 2018 11:04 am

oxidation state of MnO4-

Postby Joanna Pham - 2D » Fri Feb 22, 2019 12:12 pm

For the example Professor Lavelle did in lecture Wednesday, 2/20/19, he said the oxidation state of MnO4- was +7. Can someone please explain why the oxidation number +7 please? I am confused how to find the oxidation state for metals in the d-block.

Swetha Ampabathina1I
Posts: 64
Joined: Fri Sep 28, 2018 12:18 am

Re: oxidation state of MnO4-

Postby Swetha Ampabathina1I » Fri Feb 22, 2019 12:17 pm

Oxygen has an oxidation state of -2 which means overall just counting the oxygens, there is an oxidation state of -8 (4 oxygens times -2), but since Mn has an oxidation state of -1 we want to find what value added to -8 would equal -1, which in this case is +7.

Tarika Gujral 1K
Posts: 62
Joined: Fri Sep 28, 2018 12:27 am

Re: oxidation state of MnO4-

Postby Tarika Gujral 1K » Fri Feb 22, 2019 12:18 pm

Mn is determined by the oxidation state of oxygen as well as the overall charge of the compound.
Oxygen = -2
Because there are 4 Oxygens and overall charge is -1, we need a +7 to balance it out.
Thus, Mn is +7

makenzie2K
Posts: 31
Joined: Fri Sep 28, 2018 12:20 am

Re: oxidation state of MnO4-

Postby makenzie2K » Fri Feb 22, 2019 4:23 pm

In general, we take what we know and use it to find the missing piece, in this case the oxidation state of Mn. Since we know that the oxidation state of O2 is always going to be 2- and the other oxidation states are given as superscripts, we can deduce that the charge of Mn must be +7. This method can be applied to any redox reaction in which a "piece of the puzzle" is missing.


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