## Coordination Number

Baoying Li 1B
Posts: 91
Joined: Sat Aug 17, 2019 12:18 am

### Coordination Number

How do you know the coordination number of a complex? Like Ba[FeBr4]2

MinuChoi
Posts: 80
Joined: Wed Sep 18, 2019 12:15 am

### Re: Coordination Number

Coordination number is how many ligands are directly bonded to the central atom. This is basically everything in the coordination sphere, so
coordination number = number of ligands in the bracket.

For your example: in the bracket are 4 ligands (Br4) bound to the transition metal. The coordination number is 4.

Leyna Dang 2H
Posts: 82
Joined: Thu Jul 25, 2019 12:17 am

### Re: Coordination Number

You can determine the coordination number by counting the number of ligands that are bonded with the central atom. For Ba[FeBr4]2, you would focus on what is in the bracket. Iron, the transition metal, has 4 ligands bonded to it. Therefore, the coordination number for your example would be 4.

J Medina 2I
Posts: 78
Joined: Wed Sep 25, 2019 12:17 am

### Re: Coordination Number

However many ligands are attached to the central atom is what determines the coordination number. You can determine this by looking inside the brackets.

Jorge Ramirez_4H
Posts: 54
Joined: Wed Nov 21, 2018 12:19 am

### Re: Coordination Number

Is there a good way of memorizing this?

Gabriella Bates 2L
Posts: 87
Joined: Thu Jul 11, 2019 12:15 am

### Re: Coordination Number

Jorge Ramirez_4H wrote:Is there a good way of memorizing this?

You don't need to memorize the coordination number for each coordination compound. Just look at the number of ligands in the square brackets of the chemical formula and you should be able to find it.

Jillian C 4C
Posts: 51
Joined: Sat Jul 20, 2019 12:16 am

### Re: Coordination Number

Coordination number is the number of ligands bonded to the central atom. The coordination number of Ba[FeBr4]2 is 4 since there are 4 ligands bonded to the Fe atom.