Example Problem

[BaileyB1F]

I'm having trouble with finding the oxidation state of transition metals and was hoping someone could explain this example to me: Ag and (NH3)2
Thank you

[Khoa Vu 3l]

The oxidation state of the transition metal is another term for its charge. To find the oxidation state of Ag in Ag and (NH3)2, we would need to know the charge of the entire coordination complex. For example, in [Ag(NH3)2]+, you would need to total the charges of the transition metal and its ligands so that it would equal +1. Knowing that NH3 is a neutral ligand with a charge and oxidation state of 0, Ag would need an oxidation state or number of +1 in order for the coordination compound to have the desired charge of +1. Therefore, the name of the coordination compound would be diamminesilver (I).

[Eliot Kagan 2G]

For future reference, I think it is also good to memorize the specific charge for the ligands so you can easily find the charge (or oxidation) of the transition metal.

[Ellison Gonzales 1H]

The oxidation state of the transition metal is another term for its charge. To find the oxidation state of Ag in Ag and (NH3)2, we would need to know the charge of the entire coordination complex. For example, in [Ag(NH3)2]+, you would need to total the charges of the transition metal and its ligands so that it would equal +1. Knowing that NH3 is a neutral ligand with a charge and oxidation state of 0, Ag would need an oxidation state or number of +1 in order for the coordination compound to have the desired charge of +1. Therefore, the name of the coordination compound would be diamminesilver (I).

How did you know the charge of the whole coordination complex was +1? Or is that something that will be given?

[Khoa Vu 3l]

The oxidation state of the transition metal is another term for its charge. To find the oxidation state of Ag in Ag and (NH3)2, we would need to know the charge of the entire coordination complex. For example, in [Ag(NH3)2]+, you would need to total the charges of the transition metal and its ligands so that it would equal +1. Knowing that NH3 is a neutral ligand with a charge and oxidation state of 0, Ag would need an oxidation state or number of +1 in order for the coordination compound to have the desired charge of +1. Therefore, the name of the coordination compound would be diamminesilver (I).

How did you know the charge of the whole coordination complex was +1? Or is that something that will be given?

It will be something that you will typically be given in a coordination compound problem.

[Samantha Pedersen 2K]

The textbook gives an easy mathematical way to find the oxidation state of transition metals in coordination compounds. I'll use Khoa's example of [Ag(NH3)2]+.

1. Multiply the quantity of each atom or ligand by its charge. You can represent the charge of the transition metal as X, because this is what we want to solve for.
- There is one atom of the transition metal and we don't know its charge, so we have 1*x. There are two molecules of NH3 and they each have a
charge of 0, so we have 2*0.

2. Set the resulting values equal to the charge of the coordination sphere (the part in brackets).
- In this case, we would have 1*X + 2*0 = +1.

3. Solve for X
- In this case, X = 1 and that is the oxidation state/charge of the transition metal!

I hope this helps!