Chemistry - Coordination Chemistry Question with Solution | TestHub

So if there are strong field ligands in complex, pairing of electrons will take place, due to which number of unpaired electrons decrease due to which magnetic moment decrease.
$\left(\mathrm{c}\right)$Splitting power of ethylenediamine (en) is greater than fluoride$\left({\text{F}}^{-}\right)$ligand therefore more energy absorbed by${\left[\text{Co}\left(\text{en}\right)\right]}^{3+}$as compared to${\left[{\text{CoF}}_{\text{6}}\right]}^{3-}$

So wave length of light absorbed by${\left[\text{Co}\left(\text{en}\right)\right]}^{3+}$is lower than that of${\left[{\text{CoF}}_{\text{6}}\right]}^{3-}$

$\text{(d) }{\mathrm{\Delta }}_{\mathrm{t}}=\frac{4}{9}{\mathrm{\Delta }}_0$

$\text{so if }{\mathrm{\Delta }}_0=18,000 {\text{cm}}^{-1}$

${\mathrm{\Delta }}_{\text{t}}=\frac{4}{9}\times 18000=8000 {\text{cm}}^{-1}$

Statement$\left(\mathrm{a}\right)$and$\left(\mathrm{d}\right)$are incorrect.