Question

[Fe(CN)6]3- should be an inner orbital complex. Ignoring the pairing energy, the value of crystal field stabilization energy for this complex is (-) _____ Δ0. (Nearest integer)

Answer 1

In [Fe(CN)6]3–, Fe is present in (+3) oxidation state Fe(III)
$⇒$ inner orbital complex
$⇒$ _d _5(with pairing)
Configuration ⇒$$t_{2g}^5
$\text{CFSE} = \frac{5 \times (-2)}{5} \Delta_0$
$=\text{CFSE} = -2\Delta_0$
So, the answer is 2.