# Oxidation States

When writing oxidation states, is there a difference between 2+ and +2?

Gokul43201
Staff Emeritus
Gold Member
I believe convention requires that you use +n or -n to represent oxidation states, and m+ or m- to denote the net chrge on some species.

Example : In the radical $SO_4^{~2-}$, the oxidation state of S is $+6$.

movies
You often see the oxidation state written in Roman numerals, so SVI in Gokul's example.

dextercioby
Homework Helper
Even with Roman numerals,u still need the sign.Dor example Sulphur:$$S^{II}$$ is it for a metalic compound or for a nonmetalic compound...???

Daniel.

movies
dextercioby said:
Even with Roman numerals,u still need the sign.Dor example Sulphur:$$S^{II}$$ is it for a metalic compound or for a nonmetalic compound...???

Daniel.
True! I should have written S+VI.

Often times I think that the '+' is assumed unless you use a '-'

dextercioby
Homework Helper
The distinction needs to be done each time an nonmetalic compound experinces more than one ON,and of opposite signs.
So u may use the Roman Numerals at free will,just along you assure yourself that your notation will not raise confusions among the readers...

Daniel.

Gokul43201
Staff Emeritus
Gold Member
I have never come across the notation, $Fe^{+II}$ , for example. I've usually seen Roman Numerals designate oxidation states in complexes, but then the oxidation state appears in brackets, not as a superscript.

Ex : dichlorotetramminecobalt(III) chloride

Gokul43201 said:
I have never come across the notation, $Fe^{+II}$ , for example. I've usually seen Roman Numerals designate oxidation states in complexes, but then the oxidation state appears in brackets, not as a superscript.

Ex : dichlorotetramminecobalt(III) chloride
I must say that I have never come across Roman Numerials in formulae either. Is there an reason to use one instead of the other or are they interchangeable???

chem_tr