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### How to Find the Roman Numeral

Posted: Sun Dec 01, 2019 11:29 am
I already asked what the roman numeral represents, but this time I'm asking how do you find it?
For example, if the compound was [Co (NH)3 (H2O)3]2 (SO4^-2)3 what would the name and roman numeral be?

### Re: How to Find the Roman Numeral

Posted: Sun Dec 01, 2019 11:36 am
So that coordination compound is shown to be neutral. So you would find the net negative charge of 3 So4^2-, which is -6 (3 times -2). In the cation, NH3 and H2O are both neutral so Cobalt is the only component that has a charge which is +3.
Overall, its a net positive charge of +6 since (2 times 3 = 6).

Therefore, the whole compound is neutral. (6-6 = 0 charge)

### Re: How to Find the Roman Numeral

Posted: Sun Dec 01, 2019 12:43 pm
Typically you want to find it by process of elimination. See what the overall charge of the coordination compound is, and then determine what components inside are that make it up. From there, the roman numeral will take on whatever value it needs to be so that the components equal the total charge. Hope this helps!

### Re: How to Find the Roman Numeral

Posted: Sun Dec 01, 2019 1:08 pm
so is it usually the charge found for the transition metal

### Re: How to Find the Roman Numeral

Posted: Sun Dec 01, 2019 2:10 pm
Work backwards from the overall charge and charge of the ligands to find the charge on the metal.