Question

The crystal field splitting energy $ (CFSE) $ for $ [CoCl_{6}]^{4-} $ is about $ 18000 \, cm^{-1} $ What would be the $ CFSE $ value of $ [CoCl_{4}]^{2-} $ ?

• A. $ 18000\, cm^{-1} $
• B. $ 8000\, cm^{-1} $
• C. $ 16000\, cm^{-1} $
• D. $ 2000\, cm^{-1} $

Answer 1

Answer: (B)

The crystal field energy of tetrahedral and octahedral complex are related as : $\Delta_{t} =\frac{4}{9} \Delta_{o} $
Given : $\Delta_{o}=18000\, cm^{-1}$
$\therefore \Delta_{t}=\frac{4}{9}\times18000 \,cm^{-1}$
$\Delta_{t}=8000 \,cm^{-1}$