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roman numerals

Posted: Mon Nov 25, 2019 5:24 pm
by Katherine Wu 1H
I'm confused to what the roman numeral refers to.
In [Ni(CN)4]^-2, the name is tetracyanonickelate (II), so I'm guessing it refers to the -2?

Re: roman numerals

Posted: Mon Nov 25, 2019 5:31 pm
by Cynthia Gong 1L
I believe the II refers to the +2 charge of the nickel in the compound.

Re: roman numerals

Posted: Mon Nov 25, 2019 5:32 pm
by Anna Heckler 2C
The roman numeral indicates the charge of the ion. They are used for elements that can have ions with multiple different charges as a way to specify.

Re: roman numerals

Posted: Mon Nov 25, 2019 6:46 pm
by Naneeta Desar 1K
Many of the transition metals have multiple charged ions therefore the roman numerals clarifies and distinguishes them.

Re: roman numerals

Posted: Mon Nov 25, 2019 7:13 pm
by Megan Cao 1I
the roman numerals refer to the oxidation number of the metal atom/ion

Re: roman numerals

Posted: Mon Nov 25, 2019 7:14 pm
by Mariepahos4D
The roman numerals refer to the charge of the metal in the compound because many metals have multiple possible oxidation states so when writing out the name you would use the roman numerals to specify the charge of the ion. But when writing out the formula you would not include the numerals.

Re: roman numerals

Posted: Mon Nov 25, 2019 9:20 pm
by Jainam Shah 4I
The roman numeral refers to the oxidation state of the transition metal. Many transition metals can have different charges. Further with the Roman numeral you can figure out the charge of a ligand by comparing the charge on the transition metal and the overall charge on the entire complex. For example if you have a complex with nickel and a ligand and the overall complex charge is -1, you can deduce that the ligand's charge should be -3. Nickel has a +2 charge, the ligand has a -3 charge hence the -1 overall charge.

Re: roman numerals

Posted: Mon Nov 25, 2019 10:34 pm
by kristi le 2F
The roman numerals refer to the oxidation number of the central metal atom or ion. It can be determined by finding the difference between the charges of the ligands and the overall charge of the molecule.