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 ${\left[{\mathrm{CoCl}}_6\right]}^{4-}=18000{\mathrm{cm}}^{-1}$

$\mathrm{CFSE}\left({\Delta }_{\mathrm{t}}\right)$ of ${\left[{\mathrm{CoCl}}_4\right]}^{2-}=$ ?

From formula, ${\Delta }_t=\frac{4}{9}\times {\Delta }_0$

$=\frac{4}{9}\times 18000c{m}^{-1}$

$=8000c{m}^{-1}$