Oxidation Number

Posts: 134
Joined: Sat Sep 14, 2019 12:17 am

Oxidation Number

How do you determine the oxidation number of a metal in a complex ion?

Thank you!

Ruby Tang 2J
Posts: 102
Joined: Fri Aug 30, 2019 12:15 am

Re: Oxidation Number

If you were just given the ion, you would first find the total charge of the ligands and identify the overall charge of the ion. The charge of the metal + the total charge of the ligands should add up to the overall charge of the ion. For example, if you were given [Co(CN)6]-3, you would identify that each CN has a charge of -1, and since there are 6 of them, the CN ligands are contributing -6 to the overall charge. However, you are also given that the overall charge of the ion is -3, which means that the Co atom must have a charge of +3 since +3-6=-3.

Posts: 134
Joined: Sat Sep 14, 2019 12:17 am

Re: Oxidation Number

How would the calculations differ if the ligand was neutral?

Sarah Nichols 4C
Posts: 52
Joined: Sat Aug 24, 2019 12:18 am

Re: Oxidation Number

Ghadir Seder 4F wrote:How would the calculations differ if the ligand was neutral?

If the ligand was neutral, you would still do the calculations the same way. If the compound has a net charge but the ligands are all neutral, then that net charge must come from the metal ion and its oxidation state would equal this net charge.