Calculate the number of unpaired electrons in the following gaseous ion: `Mn^(3+) , Cr^(3+),V^(3+)` and `Ti^(3+)`. Which one of these is the most stable in aqueous solution?

Explanation

`Mn^(3+) = 3d^(4) = 4` unpaired electron, `Cr^(3+) = 3 d^(3) = 3` unpaired electrons, `V^(3+) = 3d^(2) = 2` unpaired electrons, `Ti^(3+) = 3d^(1) = 1` unpaired electron. `Cr^(3+) ` is most stable out of these sin aqueous solution because it has half- filled `t_(2g)` level `(i.e., t_(2g)^(3))` discussed in unit .