Consider the following complex ions, (P, Q) and (R). (P=\[Fe... | Chemistry | SolveeIt

Question

Consider the following complex ions, $P, Q$ and $R$ . $P=[FeF_6]^{3-},Q=[V(H_2O)_6]^{2+} and \, R=[Fe(H_2O)_6]^{2+}$ The correct order of the complex ions, according to their spin-only magnetic moment values (in $B.M.$ ) is

$R < Q < P$

$Q < R < P$

$R < P < Q$

$Q < P < R$

Answer

$Q < R < P$

Explanation

Solution

PLAN Spin only magnetic moment have the formula $\sqrt {n(n+2)} BM,$
where N is tr.e number of unpaired electrons. In the presence of
weak ligand (as $H_2O,CI^-,F^-)$ there is no pairing of electrons,
and electrons donated by ligands are filled in outer vacant
orbitals
In the presence of strong ligand (as $CN^-,CO,NH_3,en)$
electrons are paired and electrons from ligands are filled in
available inner orbitals
Thus, order of spin-only magnetic moment = Q < R < P

Chemistry Question on coordination compounds

Solution