oxidation state (2 Viewers)

[Bob.]

does an oxidation state of 1 mean that its +1 or that its -1? and when an oxidation state changes does that mean its losing electrons or gaining?

 

[pLuvia]

Oxidation state of 1 means +1, depends, if it increase then there is a loss of electrons and vice versa

 

[Tim035]

Basically you have to look at the charge of the anion the element its asking for the oxidation state is bonded with eg. I know this isn't accurate at all but if you had Cu03 . Oxygen has a charge of -2 and theirs three of them so that = - 6. So inorder for this compound to be electron happy the Copper must have an oxidation state of +6. Hope this makes sense.

 

[angmor]

for the above example, you can do it mathematically which is somewhat easier.

say CuO3 has a total net charge of zero. you want to find the oxidation state of Cu. since oxygen has an ionic charge of -2, you let Cu be x. therefore

x + -2(3) = 0
x = 6

another example would be to find the oxidation state of S in PbS04 for example.
Pb has a charge of +2 (i think). so
2 + x + -2(4) = 0
x = 6
therefore oxidation state of sulfur is 6.

hope this helps. (the ionic charge can be found by looking at the group number, or knowing the number of valence electrons in the shell)