Question

Which of the following complex has five unpaired electrons?

• A. $\left[Mn\right(H_{2}O{)}_6{]}^{2+}$
• B. $\left[Mn\right(CN{)}_6{]}^{3-}$
• C. $\left[{CrCl}_3\right(H_2{O}_3]$
• D. $\left[Ag\right({NH}_3{)}_2{]}^{+}$

Answer 1

Answer: (A)

$\left[Mn\right(H_{2}O{)}_6{]}^{2+}$

$M{n}^{2+}$ has $d^5$ configuration, since $H_{2}O$ is weak ligand field, so it does not causes pairing of electrons and hence it has 5 unpaired electrons.