Calculate the number of unpaired electrons and LFSE of [ Fe ( H2O)6 ]+3 ion .

The IUPACname of the above complex ion is hexaaquo iron(III) ion. The oxidation state of iron in this complex ion is +3 .

The valence shell electronic configurationof : [Ar] 3d5.
The arrangement of the complex ion is octahedral . The octahedral structure of this complex are as follows ,

Ligand H2O, which is a weak field Ligand . Under the influence of the octahedral crystal field, the five degenerate d-orbital’sof Fe+3 ion are splitted into two sets of energetically different orbital’s. t2g orbital and energetically higher eg orbital .

As there are five electrons in the 3d5 degenerate orbital’s , so according to crystal field theory the possible arrangementis t 2g3, eg2.

Here, the crystal field splitting energy ( 10 Dq o ) is lower than pairing energy (P).

So, no pairing of electrons will be occuredin any sets of orbital’s .

The crystal field splitting of degenerate d-orbital’s ofFe +3 ionunder the influence of Ligand weak field LigandH 2 O are as follows,

Since H 2O is a weak field Ligand , so it should be high spin complexand from the above splitting diagram ,it is clear that the complex ion have five unpaired electron .

Due to presence of five unpaired electron , the [ Fe( H2O)6 ]+3complex ion exhibit paramagnetic properties .

Calculation of Ligand field stabilization energy .

The Ligand field stabilization energy ( LFSE ) of the above complex ion is,

3x( -4 Dqo ) + 2 x 6 Dqo
= — 12 Dqo + 12 Dqo
= 0 Dqo .

Summary:

Calculate the number of unpaired electrons and LFSE of [ Fe ( H2O)6 ]+3ion .

What is ligand field stabilization energy ?

Calculate the spin only magnetic momentum µ of K3 [ Mn(CN)6] compound .

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