Considering H2O as a weak field ligand, find the number of unpaired electrons in [Mn(H2O)6]2+ .(At. no. of Mn = 25)

Since H2O is a weak ligand, it will not cause pairing of electrons in the metal ion Mn2+. Thus electronic configuration of the metal (Mn2+) in the complexwill beMn 25 2+:1s22s22p63s23p63d5i.e. 5 unpaired electrons.