Question

The crystal field splitting energy (CFSE) for ${\left[CoC{l}_6\right]}^{4-}$ is about 18000 $c{m}^{-1}$ . What would be the CFSE value for $[CoC{l}_4{]}^{2-}$ ?

Answer 1

Answer: 8000

$\mathrm{CFSE}\left({\Delta }_0\right)$ of ${\left[CoC{l}_6\right]}^{4-}=18000c{m}^{-1}$
$\mathrm{CFSE}\left({\Delta }_t\right)$ of ${\left[CoC{l}_4\right]}^{2-}=?$
From formula, ${\Delta }_t=\frac{4}{9}\times {\Delta }_0$
$=\frac{4}{9}\times 18000c{m}^{-1}$
$=8000c{m}^{-1}$