Question

In which structure crystal field splitting energey `(CFSE)` for octahedral complex will be zero when `DeltaltP` .
A. `d^(5)`
B. `d^(6)`
C. `d^(8)`
D. `d^(10)`

Answer 1

Correct Answer - d
If `Delta lt P` weak field no pairing `d^(5) = (t_(2g)^3e_(g)2)`
CFSE = -` 0 .4 xx 3 + 2 xx 1.6 = 0`
If `DeltagtP` strong field pairing `d^(5) = t_(2g) 5 e_(g)^(0)`
CFSE = `- 0 .4 xx 5 = - 2Delta`
For `d^(10) , implies t_(2g) 6 e_(g)^(4) = - 0.4 xx 6 + 0.6 xx 4 =0` .