Question

Calculate the total number of unpaired electrons in [Co(H${}_2$O)${}_6$]${}^{2+}$.

Answer 1

$\left[Co\right(H_{2}O{)}_6{]}^{2+}$ has three unpaired electrons. It has $3d^7$ outer electronic configuration which can also be written as $t_{2g}^5{e}_g^2$.