The d electron configurations of `Cr^(2+),Mn^(2+),Fe^(2+)" and "Ni^(2+)" are "3d^(4),3d^(5), 3d^(6)" and "3d^(8)` respectively. Which one of the following aqua complexes will exhibit the minimum paramagnetic behaviour? (At. no. of Cr= 24, Mn= 25, Fe= 26, Ni= 28)

Options

A. `[Fe(H_(2)O)_(6)]^(2+)`
B. `[Co(H_(2)O))_(6)]^(3+)`
C. `[Mn(H_(2)O)_(6)]^(2+)`
D. `[Ni(H_(2)O)_(6)]^(2+)`

Answer

B

Explanation

`[Co(H_(2)O)_(6)]^(3+)=d^(2)sp^(3)`
low spin, diamagnetic,magntic moment = zero `BM` .