Question
Chemistry Question on d -and f -Block Elements
[Fe(CN)6]4−,[V(CN)6]4−,[Cr(NH3)6]2+ and [Ru(CN)6]3− Find the decreasing order of spin only magnetic moment
A
\ce[V(CN)6]4−>[Cr(NH3)6]2+>[Ru(CN)6]3−>[Fe(CN)6]4−
B
\ce[Fe(CN)6]4−>[V(CN)6]4−>[Cr(NH3)6]2+>[Ru(CN)6]3−
C
\ce[Ru(CN)6]3−>[Fe(CN)6]4−>[V(CN)6]4−>[Cr(NH3)6]2+
D
\ce[Cr(NH3)6]2+>[Ru(CN)6]3−>[Fe(CN)6]4−>[V(CN)6]4−
Answer
\ce[V(CN)6]4−>[Cr(NH3)6]2+>[Ru(CN)6]3−>[Fe(CN)6]4−
Explanation
Solution
CN−&NH3 are strong field ligands. V2+−>[Ar]3d3−>3unpairedelectrons Cr2+−>[Ar]3d4−>2unpairedelectrons Ru3+−>[Kr]4d5−>1unpairedelectron Fe2+−>[Ar]3d6−>0unpairedelectrons