Question

The CFSE for octahedral $[CoC{l}_6{]}^{4-}$ is $18,000c{m}^{-1}$. The CFSE for tetrahedral $[CoC{l}_4{]}^{2-}$ will be:

• A. $18,000c{m}^{-1}$
• B. $16,000c{m}^{-1}$
• C. $8,000c{m}^{-1}$
• D. $20,000c{m}^{-1}$

Answer 1

The correct option is C $8,000c{m}^{-1}$

${\Delta }_t=\frac{4}{9}\times {\Delta }_o$

Where ${\Delta }_t=$ CFSE for tetrahedral complex.

${\Delta }_o=$ CFSE for octahedral complex.

${\Delta }_t=\frac{4}{9}\times (18,000c{m}^{-1})=8000c{m}^{-1}$

Hence option C is correct.