Question

What are the spin-only magnetic moments (in BM) for Ni(II) ion in square-planar and octahedral geometry, respectively?

• A. 0, 2.83
• B. 2.83, 2.83
• C. 2.83, 0
• D. 0, 0

Answer 1

Answer: (A)

0, 2.83

In square planar geometry, $N{i}^{2+}$ orbitals are

$\uparrow \downarrow \uparrow \downarrow \uparrow \downarrow \uparrow \downarrow$

The empty orbital is for hybridization. There are no unpaired electrons here.

Magnetic Moment: $\sqrt{n(n+2)}BM$ where ${}^{\prime }{n}^{\prime }$ is number of unpaired electrons.

Here, magnetic moment $=\sqrt{0(0+1)}=0$

In octahedral geometry, $N{i}^{2+}$ obitals are

$\uparrow \downarrow \uparrow \downarrow \uparrow \downarrow \uparrow \uparrow$

Here, it has $2$ unpaired electrons.

$MagneticMoment=\sqrt{2(2+2)}=\sqrt{2\left(4\right)}=2\sqrt{2}=2.828=2.83$