Calculate the number of unpaired electrons in the following gaseous ions: `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 electrons, `Cr^(3+)=3d^(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 in aqueous solution bacause it has half filled `t_(2g)^(3)`.