Question

There are three unpaired electrons in $\left[Co\right(H_{2}O{)}_6{]}^{2+}$ and calculated value of magnetic moment is $3.87$ BM which is quite different from the experimental value of $4.40$ BM. This is because of :

• A. increasing in number of unpaired electrons during determination
• B. some contribution of the orbital motion of the electron to the magnetic moment
• C. experimental error
• D. $d-d^{\ast }$ transition

Answer 1

The correct option is B some contribution of the orbital motion of the electron to the magnetic moment

As we know,
magnetic moment $\mu =\sqrt{n(n+2)}$
$\left[Co\right(H_{2}O{)}_6{]}^{2+}$ have three unpaired electron so its calculated value of magnetic moment is $3.87$ BM but it has also some contribution form orbitals angular momentum and its value found is $4.40$ BM.