question_answer 34)

  Calculate the number of unpaired electrons in the following gaseous ions : Mn3+, Cr3+, V3+ and Ti3+ Which one of these is most stable in aqueous solution?

Answer:

Mn3+         :               [Ar] 3d4;               Four unpaired electrons Cr3+             :               [Ar] 3d3;               Three unpaired electrons V3+               :               [Ar] 3d2;               Two unpaired electrons Ti3+         :               [Ar] 3d1;               One unpaired electron Out of these, Cr3+ is most 'stable in aqueous solution because it has half Filled t2g level (i.e., t32 g)