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` No. of unpaired electrons = 4
`Cr^(3+) : 3d^3` No. of unpaired electrons = 3
`V^(3+) : 3d^2` No. of unpaired electrons = 2
` Ti^(3+) : 3d^1` No. of unpaired electrons = 1
`Cr^(3+)` is most stable in aqueous solution.