Question

Select the correct I.U.P.A.C. name for [PtCl${}_6$]${}^{2-}$:

• A. Hexachloridoplatinate (IV) ion
• B. Hexachloridoplatinum (II) ion
• C. Hexachloridoplatinate (2-) ion
• D. Hexachloridoplatinum (2-) ion

Answer 1

Answer: (A), (C)

The correct options are
A Hexachloridoplatinate (IV) ion
C Hexachloridoplatinate (2-) ion

The stoek system puts the calculated oxidation number of the metal ion as a Roman numeral in parentheses after the name of the metal This is the more common convention, although there are cases in which it is difficult to assign oxidation numbers.
The Ewing-Bassett system puts the charge on the coordination sphere in parentheses after the name of the metal. This convention is used by chemical abstracts and offers an unambiguous identification of the species.
[PtCl${}_6$]${}^{2-}$
Hexachloridoplatinate (2-) ion
Hexachloridoplatinate (IV) ion