Question

Calculate CFSE (in terms of ${\Delta }_0$ ) for $d^5-highspin$ (octahedral).

• A. $3.2{\Delta }_o$
• B. $0{\Delta }_o$
• C. $1{\Delta }_o$
• D. $2{\Delta }_o$

Answer 1

The correct option is B $0{\Delta }_o$

As it is a high spin complex, pairing of electrons is not possible, hence, 3 electrons are in $t_{2}g$ level and 2 electrons are in $e_g$ level, since it has an octahedral geometry.

Thus,

$CFSE=2\times 0.6{\Delta }_o-3\times 0.4{\Delta }_o=0{\Delta }_o$