Question

$\left[Co\right(H_{2}O{)}_6{]}^{2+}$ has three unpaired electrons and has a calculated value of magnetic moment as $3.87$ BM, which is quite different from the experimental value of $4.40$ BM. This is due to:

• A. increase in number of unpaired electrons
• B. some contribution of the orbital motion of an electron to the magnetic moment
• C. change in orbital spin of an electron
• D. $d-d$ transition

Answer 1

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

There are three unpaired electrons in $\left[Co\right(H_{2}O{)}_6{]}^{2+}$ and calculated value of magnetic moment is $\mu =\sqrt{n(n+2)}=3.87$ BM

However, due to some contribution of the orbital motion of an electron to the magnetic moment, its experimental value is found to be $4.40$ BM.