## Determining Oxidation Numbers

FDeCastro_1B
Posts: 54
Joined: Thu Jul 25, 2019 12:16 am

### Determining Oxidation Numbers

Can someone please explain how to find the oxidation number of a chemical compound?

Feel free to use K2[Ni(CN)4] as an example if it makes it any easier.

Ryan Yee 1J
Posts: 101
Joined: Sat Aug 17, 2019 12:16 am

### Re: Determining Oxidation Numbers

The name of this compound is potassium tetra cyano nickelate (II). This is because it is an ion that forms with potassium and the nickelate coordination compound. The (II) refers to the oxidation state of the nickel in the compound and comes from the charge of the nickel. Because the overall charge of the [Ni(CN)4] is 2- and the charge of CN is 1-, you add all the charges to get a charge of 4-, which must be offset by nickel's charge of 2+ to get the overall charge of 2-. So because nickel's charge is 2+, its oxidation number is (II).

Daniel Honeychurch1C
Posts: 109
Joined: Thu Jul 11, 2019 12:15 am

### Re: Determining Oxidation Numbers

For K2[Ni(CN)4],

2 K+ ions (total +2 charge)

1 Ni atom (charge ?)

4 CN- ions (total -4 charge)

The entire compound is neutral.

Therefore, 0 = 2 + oxidation number of Ni + -4
oxidation number of Ni = 2