3 Answers 3 Sorted by:
The sum of the oxidation states of all of the atoms needs to equal the total charge on the ion.
For example, for $ce{NH4+}$, if each hydrogen atom has an oxidation state of +1, and the overall charge is +1, then we can solve for the oxidation state of nitrogen:
$$begin{aligned} 4(+1) + OS_ce{N} &= +1\ OS_ce{N} &= +1 -4(+1) \ OS_ce{N} &= -3 end{aligned}$$
Similarly, we can do $ce{SO4^2-}$. If each oxygen atom has an oxidation state of -2, and the overall charge is -2, we can solve for the oxidation state of sulfur:
$$begin{aligned} 4(-2) + OS_ce{S} &= -2\ OS_ce{S} &= -2 -4(-2) \ OS_ce{S} &= +6 end{aligned}$$
Seeing as Oxygen has an oxidation state of -2 and you have 4 Oxygen atoms, the total charge contributed by Oxygen = -8. Because the total charge of this compound = -1, then in this case Mn = +7 +7 – 8 = -1
As you said Oxygen has the oxidation state of -2 so if we add up all the oxygens they have a -8 oxidation state.
As the oxidation state of the ion is equal to its charge, the Mn has to “balance” the -8 to get it up to -1. Therefore the oxidation state of Mn in Mno4- is +7.
Thanks for contributing an answer to Chemistry Stack Exchange!
Use MathJax to format equations. MathJax reference.
To learn more, see our tips on writing great answers. Draft saved Draft discarded
hello everyone here are the cause and oxidation number of MN in KMnO4 – is + 4 is it true or false so here we calculate the oxidation number for payment in Amazon offer – 4 – Sohail let it be the oxidation number of MN b x and we know that the charge of oxygen is -2 and here are the charge of whole molecule is -1 so is it this is equal to -1 if it is not also it is equal to zero but here it is charges given the charges present at this molecule or these compounds show it is equal to -1 so here it is me x minus 8 is equal to minus x is equal to 8 minus one that is equal to 1 + 7 so here the oxidation number of MN
in mno4 – + 7 but here it is given that oxidation number of MN in KMnO4 is plus 4 so it is the false it is false thank you Click here to get PDF DOWNLOAD for all questions and answers of this Book – AAKASH INSTITUTE ENGLISH Class 12 CHEMISTRY
∴ x = +7 Concept: Oxidation States of First Transition Series Is there an error in this question or solution? Advertisement
