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Oxidation Numbers

Posted: Sun Nov 26, 2017 10:30 pm
by camrynpatterson3C
I know the roman numerals in a compound is the oxidation number for the metal, but I don't know exactly what an oxidation number means or how to find it. Am I crazy, or did Lavelle not teach that?
So, how do we find the oxidation number of a compound? Also, when given the oxidation number in the name of a compound (i.e. question 17.31; potassium hexacyanidochromate(III)), what does it tell us about the formula of the compound?

Re: Oxidation Numbers

Posted: Sun Nov 26, 2017 11:26 pm
by Katie Lam 1B
The oxidation number refers to the charge of the ion. You determine the oxidation number by comparing the overall charge of the compound to the charges of anions within the compound in order to determine the charge on the transition metal cation.

Re: Oxidation Numbers

Posted: Sun Nov 26, 2017 11:30 pm
by Sean Monji 2B
edit: ^ sums it up

The numerals represent how many electrons the metal atom lost. Oxidation is simply the loss of electrons, thus it is called oxidation number. To find the oxidation number, you need to look at the total charge of the atom(s) or molecule(s) attached to the metal. In the example given, potassium is bonded with ligands which have a net charge of 3-. If the ligands have a net charge of 3- and the whole compound has a net charge of 0, then potassium must have an oxidation number of 3 (III). I think we were supposed to know oxidation numbers from high school chem, you're alright.