Q. Which of the following complex has zero magnetic moment (spin only)?
A) $\left\lbrack Ni\left( {NH}_{3} \right)_{6} \right\rbrack{Cl}_{2}$
B) ${Na}_{3}\lbrack{FeF}_{6}\rbrack$
C) $\left\lbrack Cr\left( H_{2}O \right)_{6} \right\rbrack{SO}_{4}$
D) $K_{4}\lbrack Fe(CN)_{6}\rbrack$
Explanation
(d)
Ferrocyanide ion $\left\lbrack Fe(CN)_{6} \right\rbrack^{4 -}$ is diamagnetic in nature hence $K_{4}\lbrack Fe(CN)_{6}\rbrack$ complex has zero magnetic moment.
Fe-atom 3$d$ 4$s$ 4$p$
[table] ⥮ | $\upharpoonleft$ | $\upharpoonleft$ | $\upharpoonleft$ | $\upharpoonleft$ | | ⥮ | | | | [/table]
Fe(II)
[table] ⥮ | $\upharpoonleft$ | $\upharpoonleft$ | $\upharpoonleft$ | $\upharpoonleft$ | | | | | | [/table]
$d^{2}\ sp^{3}$ hybridisation
[image:9_image259.emf]
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.