Question

Considering $H_{2}O$ as a weak field ligand, the number of unpaired electrons in $\left[Mn\right(H_{2}O{)}_6{]}^{2+}$ will be:

(At. no. of $Mn=25)$

• A. three
• B. five
• C. two
• D. four

Answer 1

The correct option is B five

The oxidation number of manganese of $\left[Mn\right(H_{2}O{)}_6{]}^{2+}$ is +2. The electronic configuration of $M{n}^{2+}$ is $\left[Ar\right]3d^5$ and hence the number of unpaired electrons are five.