Question

The crystal fied stabilization energy (CFSE) of $[Fe(H_2O)_6]Cl_2 $ and $K_2[NiCl_4]$, respectively, are :-

• A. $-0.4 \Delta_{O} \;$ and $\; -0.8 \Delta t$
• B. $-0.4 \Delta_{O} \; $ and $ \; -1.2 \Delta t$
• C. $-2.4 \Delta_{O} \;$ and $\; -1.2\Delta t$
• D. $-0.6 \Delta_{O} \;$ and $\; -0.8 \Delta t$

Answer 1

Answer: (A)

$\left[ Fe \left( H _2 O \right)_6\right] Cl _2, Fe ^{2+} \longrightarrow 3 d _6 \rightarrow\left( t _{2 g }\right)_4\left( e _{ g }\right)^2$
$C \cdot F \cdot S \cdot E \cdot 4 \times(-0 \cdot 4 \Delta o )+2 \times 0 \cdot 6 Do =-0 \cdot 4 \Delta o$
$K _2\left[ NiCl _4\right], Ni ^{2+} \rightarrow 3 d _8 \rightarrow( e )^4\left( t _2\right)^4$
$C \cdot F \cdot S \cdot E \cdot=4 \times(-0 \cdot 6 \Delta t )+4 \times(0 \cdot 4 \Delta t )=-0 \cdot 8 \Delta t$