Question

The correct I.U.P.A.C. name for ${\text{H}}_2\left[\text{PtC}{\text{l}}_6\right]$ complex:
A. Hexachloridoplatinic (IV) acid
B. Hexachloridoplatinate (IV) acid
C. Hydrogenhexachloridoplatinate (IV) acid
D. Dihydrogen hexachloroplatinate (IV) acid

Answer 1

Hint: First understand the compound structure and functional groups attached to it; by it we can determine the IUPAC name. To name any compound, there are certain sets of rules to be followed to write IUPAC names. Calculate the oxidation state of the central metal ion and then count the number of ligands attached to it before naming the compound.

Complete answer:
- First find the oxidation state of central metal atom which is $\text{Pt}$ in ${\text{H}}_2\left[\text{PtC}{\text{l}}_6\right]$. The compound has six ligands. Let the oxidation state of $\text{Pt}$be x. Hence, the oxidation will be$[(1\times 2)+\left(\text{x}\right)+(-1\times 6)]=0$; so x equals to +4. The oxidation state of$\text{Pt}$is +4. The oxidation state while writing IUPAC name is written in roman numerals inside brackets.
- If cations are present outside the parentheses, then ‘ate’ is added to the name of central metal at the end; the platinum will be platinumed. The number of hydrogen atoms are 2, so the name of ${\text{H}}_2$will be dihydrogen. The number of chlorine atoms are 6, so the name will be ‘hexachlorido’. The IUPAC name is written in alphabetical order.
The IUPAC name of ${\text{H}}_2\left[\text{PtC}{\text{l}}_6\right]$ will be Dihydrogen hexachloroplatinate (IV) acid.
The correct answer is option ‘d’.

Additional Information:
Chloroplatinic acid or hexachloroplatinic acid is a catalyst or precatalyst used for hydrogenation. It is an inorganic compound and a red solid; it is an important commercial source of platinum.

Note: The name of the compound is written with substituents in alphabetical order followed by its base name. Between numbers, commas are used and dashes are used between letters and numbers.