Question

The $EAN$ of platinum in potassium hexachloroplatinate (IV) is:

• A. $36$
• B. $46$
• C. $86$
• D. $84$

Answer 1

The correct option is C $86$

Effective atomic number(EAN), a number that represents the total number of electrons surrounding the nucleus of a metal atom in a metal’s complex. It is composed of the metal atom’s electrons and the bonding electrons from the surrounding electrons-donating atoms and molecules.
The mathematical expression of effective atomic number (EAN) is:
$\text{EAN = [(Atomic no. of central atom) - (Oxidation state of central atom) + (No. of electrons gained by the metal from ligands through Co−ordination)]}$
For $K_2\left[PtC{l}_6\right]$,
$\text{EAN}=\left[\right(78)-(4)+(2\times 6)=86$
Hence, option (b) is the correct answer.