Question

The effective atomic number of cobalt in the complex $\left[Co\right(N{H}_3{)}_6{]}^{3+}\text{is :}$

• A. $36$
• B. $33$
• C. $35$
• D. $30$

Answer 1

The correct option is A $36$

$EAN$ stands for effective atomic number. It is used to check the stability of organometallic compounds.
The sum of electrons on central metal atom or ion and electrons donated from ligand is called effective atomic number.
$EAN=Z-O.N+2[C.N]$
$Z-$ Atomic number
$O.N-$ Oxidation number
$C.N-$ Coordination number

For $\left[Co\right(N{H}_3{)}_4{]}^{2+}$,
$EAN=27-3+2\left(6\right)$
$EAN=36$
Hence, the correct option is A