Question

The type of magnetism exhibited by $\left[Mn\right(H_{2}O{)}_6{]}^{2+}$ ion is:

• A. paramagnetism
• B. diamagnetism
• C. both (a) and (b)
• D. none of these

Answer 1

The correct option is A paramagnetism

The given complex is [Mn (H${}_{2}O{)}_6{]}^{2+}$

The electronic configuration of Mn is [Ar] $3d^{5}4s^2$

for Mn${}^{2+}$ $\to$ {Ar] $3d^{5}4s^0$

[Ar] $\upharpoonleft$ $\upharpoonleft$ $\upharpoonleft$ $\upharpoonleft$ $\upharpoonleft$

3d 4s

3d 4s 4p 4d

So, [Mn (H${}_{2}O{)}_6{]}^{2+}$ $\to$ [Ar] $\upharpoonleft$ $\upharpoonleft$ $\upharpoonleft$ $\upharpoonleft$ $\upharpoonleft$ xx xx xx xx xx xx

$H_{2}O$

sp${}^3{d}^2$ hybridised

So, due to presence of 5 unpaired d$e^{-}$ s, it is paramagnetic.