For which of the following pairs, magnetic moment is same ?

Options

A. `MnCl_(2), CuSO_(4)`
B. `CuCl_(2), TiCl_(3)`
C. `TiO_(2), CuSO_(4)`
D. `TiCl_(3), NiCl_(2)`

Answer

B

Explanation

Species having the same number of unpaired electrons, have same magnetic moment.
(i) `MnCl_(2) rArr Mn^(2+) = [Ar]3d^(5), 4s^(0)`
(five unpaired electrons)
`CuSO_(4) rArr Cu^(2+) = [Ar]3d^(9), 4s^(0)`
(one unpaired electron)
(ii) `CuCl_(2) rArr Cu^(2+) = [Ar]3d^(9), 4s^(0)`
(one unpaired electron)
`TiCl_(3), rArr Ti^(3+) = [Ar]3d^(1), 4s`
(one unpaired electron)
`:. CuCl_(2) "and" TiCl_(3)` have same magnetic moment.
`m= sqrt(1(1+2)) = sqrt(3)` = 1.73 BM
(iii) `TiO_(2) rArr Ti^(4+) = [Ar]3d^(0), 4s^(0)`
(no unpaired electron)
`CuSO_(4) rArr Cu^(2+) = [Ar]3d^(1), 4s^(0)`
(one unpaired electron)
(iv) `TiCl_(3) rArr Ti^(3+) =[Ar]3d^(1), 4s^(0)`
(one unpaired electron)
`NiCl_(3) rArr Ni^(2+) = [Ar]3d^(8), 4s^(0)` (two unpaired electrons)