Chemical Formula

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Quynh Nguyen 2O
Posts: 27
Joined: Fri Sep 26, 2014 2:02 pm

Chemical Formula

Postby Quynh Nguyen 2O » Wed Dec 03, 2014 2:06 am

What is the difference between [CoCl(NH3)5]Cl2 and [Co(NH3)5Cl]Cl2? Why is the first chem. formula right and the second one wrong?

Vivien Ho 3L
Posts: 30
Joined: Fri Sep 26, 2014 2:02 pm

Re: Chemical Formula

Postby Vivien Ho 3L » Wed Dec 03, 2014 8:49 am

According to Toolbox 16.1 of the textbook, it says we have to write the chemical symbols of ligands in alphabetical order. Therefore, it should be Cl first then NH3.

Ryka Sehgal 3H
Posts: 10
Joined: Fri Sep 26, 2014 2:02 pm

Re: Chemical Formula

Postby Ryka Sehgal 3H » Wed Dec 03, 2014 9:51 am

Note that this same principle of writing the ligands in alphabetical order applies when naming the compound. So, [Co(NH3)5Cl]Cl2 would be "pentaamminechlorocobalt(III)chloride" NOT "chloropentamminecobalt(III)chloride". The prefixes (mono-, di-, tri-, tetra-, penta-, etc.) are disregarded when alphabetizing, focus on the name of the molecule itself. (ex. (NH3)5 is first because of the "a" in ammine, not the "p" in penta).

Justin Le 2I
Posts: 142
Joined: Fri Sep 26, 2014 2:02 pm

Re: Chemical Formula

Postby Justin Le 2I » Wed Dec 03, 2014 10:29 pm

Lavelle has also said in another post on Chemistry Community that when writing the formula, the anion ligands should be named before the neutral ligands.

Polly
Posts: 10
Joined: Fri Sep 26, 2014 2:02 pm

Re: Chemical Formula

Postby Polly » Thu Dec 04, 2014 12:29 am

Also when you write out the name the ligands go in alphabetical order based on the name of the ligand, not it's greek prefix


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