Which one of the following ions is colourless in aqueous solution ?

Options

A. `Cu^2+`
B. `Ti^2+`
C. `Ni^2=`
D. `Mn^2+`

Answer

(d)

Explanation

Magnetic moment dependeds on the number of unpaired electrons
`Cu^2+ = [Ar] 3d^9`, `n = 1 Ni^2= [Ar]3d^8`, n= 2 and `Mn^2+ = [Ar]3d^5`, n= 5
since `Mn^2+` is having maximum number of unpaired electrons its magnetic moment is highest.