Considering `H_2O` as a weak field ligand, the number of unpaired electrons in `[Mn(H_2O)_6]^(2+)` will be (At. no. of `Mn=25`)

Options

A. 3
B. 5
C. 2
D. 4

Answer

B

Explanation

In `[Mn(H_(2)O)_(6)]^(2+)` , the oxidation number of Mn is `+2`.
`Mn (3d^(5) 4s^(2)) implies Mn^(2+) (3d^(5))`
Since water is a weak field ligand, all the 5 electrons in 3d subshell remain unpaired.
`[Mn(H_(2)O)_(6)]^(2+)`
If is outer orbital complex (or high spin or free complex).