## Self-Test 2 Problem 4

604807557
Posts: 51
Joined: Wed Nov 16, 2016 3:02 am

### Self-Test 2 Problem 4

The problem is:

For the complex ions listed below, determine the oxidation state and the coordination number of the central metal ion.
[Pt(CN)(NH3)3]^+

My question is, how do you find the oxidation state? Also, I got the coordination number 4, is that correct?

sandraabdelmalak1D
Posts: 21
Joined: Wed Nov 16, 2016 3:03 am

### Re: Self-Test 2 Problem 4

I am not sure about the oxidation portion of the question either, but i also got that the coordination number is 4.

derek1d
Posts: 19
Joined: Wed Jun 28, 2017 3:00 am

### Re: Self-Test 2 Problem 4

To get the oxidation state of the central atom, you first would need to find the formal charge of all of the ligands attached to the complex.
Oxidation state of CN^- is -1 and there is one (1 x -1 = -1), and oxidation state of NH3 is 0 and there are 3 (3 x 0 =0).
Once you have those charges you can get the oxidation state of the central atom by assigning a variable to represent the charge of Pt, and set up an algebraic equation to solve for Pt charge. (Pt + 0 - 1 = 1)
We know that this equation is equal to 1 because of the given positive charge on the ligand.
After adding -1 on to each side we find that the charge of Pt = 2.
Hope this helped!