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### Quiz 3 Prep (3rd Prep) #1

Posted: Mon Nov 14, 2016 11:36 pm
For the coordination numbers, if its outside the bracket, do we count it for the coordination number?

What would be the coordination number for [Fe(ox)CO)2(NH3).H2O??? Or for Li[Ni(CN)3(en)(NH3)] (quiz 3 prep #1)

### Re: Quiz 3 Prep (3rd Prep) #1

Posted: Mon Nov 14, 2016 11:54 pm
No, you don't count the H2O when counting the coordination number.
Remember: number of bonds = coordination number

For the first coordination compound, the coordination number would be 5. Oxalato (ox) is a bidentate so it has two bonds; carbonyl (CO) is a monodentate (one bond) but because there are two in the formula, it has two total bonds; and ammine (NH3) is a monodentate so it has one bond. 2+2+1=5

For the second coordination compound, the coordination number would be 6. Cyano (CN) is a monodentate, but because there are three in the formula, it has three total bonds; ethylenediamine (en) is a bidentate so it has two bonds; and ammine (NH3) is a monodentate so it has one bond. 3+2+1=6

Hope this helps!

### Re: Quiz 3 Prep (3rd Prep) #1

Posted: Tue Nov 15, 2016 12:30 am
How can you know whether a ligand is a monodentate or bidentate etc? Other than just memorizing?

### Re: Quiz 3 Prep (3rd Prep) #1

Posted: Tue Nov 15, 2016 4:43 pm
Analiese Machado lec4 wrote:How can you know whether a ligand is a monodentate or bidentate etc? Other than just memorizing?

To be honest, I don't think there is any other way to know other than memorizing. If there is, I feel like it's beyond the scope of the class. I would just say memorize the few that are bidentates; then you know that all other ligands are monodentates.

### Re: Quiz 3 Prep (3rd Prep) #1

Posted: Tue Nov 15, 2016 5:22 pm
You can always draw them out if you are not sure. That way you can see all the bonding sites.