Question

In the complex ion $M{L}_6^{n+},M^{n+}$ has five d-electrons and $L$ is weak field ligand. According to crystal field theory the magnetic properties of the complex ion corresponds to how many unpaired electrons?

• A. $0$
• B. $5$
• C. $2$
• D. $3$

Answer 1

The correct option is B $5$

In the complex ion $[M{L}_6{]}^{n+}$ if the metal ion have 5 d electrons and L is a weak field ligand then, the number of unpaired electrons is 5 because in the case of octahedral complexes with a weak field ligand the ${\Delta }_o$ < P.E(pairing energy) and hence the electrons are filled as $t_g^{3}e{g}^2$. Therefore the correct answer is B.