Chemistry - Coordination Chemistry Question with Solution | TestHub

$\underset{\left[\mathrm{A}\mathrm{r}\right]3{\mathrm{d}}^6}{\mathrm{F}{\mathrm{e}}^{+2}}\to \underset{\left[\mathrm{A}\mathrm{r}\right]3{\mathrm{d}}^5}{\mathrm{F}{\mathrm{e}}^{+3}}$

$\mathrm{C}\mathrm{F}\mathrm{S}\mathrm{E}=6\times \left(-0.4\right){\mathrm{\Delta }}_0=-2.4{\mathrm{\Delta }}_0$
$\mathrm{C}\mathrm{F}\mathrm{S}\mathrm{E}=-2.0\mathrm{ }{\mathrm{\Delta }}_0$

In all other cases, the electron is removed from ${\mathrm{e}}_{\mathrm{g}}$ orbital and is hence, this will lead to decrease in pairing energy.