Question

The crystal fied stabilization energy $\left(CFSE\right)$ of $\left[Fe\right(H_{2}O{)}_6]C{l}_2$ and $K_2\left[NiC{l}_4\right]$, respectively, are:

• A. $-0.4{△}_o$ and $-0.8{△}_t$
• B. $-0.4{△}_o$ and $-1.2{△}_t$
• C. $-2.4{△}_o$ and $-1.2{△}_t$
• D. $-0.6{△}_o$ and $-0.8{△}_t$

Answer 1

Answer: (A)

$-0.4{△}_o$ and $-0.8{△}_t$

$a\left)\right[Fe\left(H_{2}O{)}_6\right]C{l}_2,F{e}^{2+}\to 3d^6\to \left(t_{2g}{)}^4\right(e_g{)}^2$

$C.F.S.E.=4\times (-0.4{△}_o)+2\times 0.6{△}_o=-0.4{△}_o$

$b\left)K_2\right[NiC{l}_4],N{i}^{2+}\to 3d^8\to e^4(t_2{)}^4$

$C.F.S.E.=4\times (-0.6{△}_t)+4\times \left(0.4{△}_t\right)=-0.8{△}_t$.