Question

Consider the following complex ions , P , Q and R .

P = [ FeF6 ]3- , Q = [ V ( H₂O ] and
R = [ Fe( H₂O )₆]²₊

The correct order of thee complex ions , according to their spin only maganetic ( in B. M ) is

Answer 1

P = [ FeF₆]³⁻ has Fe³⁺    = 3d⁵  ( 5 unpaired electrons ) 
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Q= [ V ( H₂O )₆]²⁺  has V²⁺ = 3d³   ( 3 unpaired  e- ) 
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R= [ Fe ( H₂O )₆]²⁺ has Fe³⁺ = 3d⁶  ( 6 unpaired e- ) 
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order  of the spin magnetic moment is  

Q < R < P  

hope it helps ; ]