## Roman Numeral

Frederick Keith_4C
Posts: 65
Joined: Thu Sep 26, 2019 12:19 am

### Roman Numeral

I see roman numerals in a lot of the coordination compounds, and I don't know what it represents. So my question is what do the roman numerals represent or mean?

DarrenKim_1H
Posts: 123
Joined: Fri Sep 20, 2019 12:17 am
Been upvoted: 1 time

### Re: Roman Numeral

It represents the positive charge on a cation. For example a copper (ii) sulfate CuSO4, represents a Cu^2+ ion which attaches itself to the sulfate anion (SO4^2-)

serenabirkhoff_1K
Posts: 63
Joined: Sat Aug 17, 2019 12:15 am

### Re: Roman Numeral

If we use the roman numeral for positive cations what do we use if the transition metal has a negative anion charge? will this happen?

Posts: 102
Joined: Wed Sep 18, 2019 12:21 am

### Re: Roman Numeral

it represents the charge of the element you are dealing with.

405268063
Posts: 102
Joined: Thu Jul 25, 2019 12:17 am

### Re: Roman Numeral

I have personally not seen an instance where the transition metal has a negative anion charge if the charge is designated by a parentheses. If I see a roman numeral, I assume it's "plus whatever that charge is" and it works for me.

Brian J Cheng 1I
Posts: 115
Joined: Thu Jul 11, 2019 12:15 am

### Re: Roman Numeral

As many have said above, it represents the (usually positive) charge of the atom it's coupled with. Usually only transition metals have this notation.

Debora Fernandez Clemente_ 4H
Posts: 52
Joined: Wed Sep 18, 2019 12:21 am

### Re: Roman Numeral

How do you calculate the oxidation number of the metal in a complex?

Cynthia Rodas 4H
Posts: 51
Joined: Wed Sep 18, 2019 12:21 am

### Re: Roman Numeral

Debora Fernandez Clemente_ 4H wrote:How do you calculate the oxidation number of the metal in a complex?

To calculate the oxidation number of the metal in a complex, you would use the equation:

(# metal atoms)(oxidation number of the metal)+$\sum$(# each ligand)(charge of each ligand)= charge of ion

cassidysong 1K
Posts: 100
Joined: Fri Aug 30, 2019 12:15 am

### Re: Roman Numeral

The roman numeral tells you the charge of the metal ion.

mayarivers3I
Posts: 52
Joined: Wed Sep 18, 2019 12:18 am

### Re: Roman Numeral

The roman numeral is the charge of the metal in the compound.

Posts: 51
Joined: Wed Sep 18, 2019 12:19 am

### Re: Roman Numeral

The roman numeral represents the oxidation state of the metal.

Posts: 51
Joined: Thu Jul 11, 2019 12:17 am

### Re: Roman Numeral

It tells you the oxidation state.

Abraham De Luna
Posts: 62
Joined: Sat Sep 14, 2019 12:16 am

### Re: Roman Numeral

The roman numeral is the charge of the metal in the compound.

Presley Gao 2C
Posts: 65
Joined: Sat Jul 20, 2019 12:15 am

### Re: Roman Numeral

The roman numerals represent the oxidation number of the metal ion.