What is the value of effective atomic number of cobalt in…
What is the value of effective atomic number of cobalt in $\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ complex if $\mathrm{Co}(\mathrm{Z}=27)$ ?
$30$
$32$
$35$
$36$
Solution
$\left[\mathrm{Co}\left(\mathrm{NH}_3\right)_6\right]^{3+}$ :
Oxidation state of cobalt is +3 and six ligands donate 12 electrons.
$\begin{aligned}
& \mathrm{Z}=27 ; \mathrm{X}=3 ; \mathrm{Y}=12 \\
& \begin{aligned}
\text { EAN of } \mathrm{Co}^{3+} & =\mathrm{Z}-\mathrm{X}+\mathrm{Y} \\
& =27-3+12=36
\end{aligned}
\end{aligned}$