Coordination Compounds

is diamagnetic ion due to absence of unpaired electron. Its geometry is octahedral.

is

Since is a strong field ligand, pairing occurs and the hybridisation of is and structure is octahedral.

Outer electronic configuration of is
Outer electronic configuration of is .
As is strong field ligand, so pairing will take place.

Usually, metal carbonyls follows EAN rule.
Among the given,
does not follow EAN rule, so it does not exist.
EAN = atomic no. of metal + electrons of ligands

In , central metal Co is present as . Because of the presence of three unpaired electrons, the complex is paramagnetic. Moreover, ions occupy outer -orbitals (ie, -orbitals), thus it is an outer orbital complex.

The IUPAC name of is potassium tri(oxalato)aluminate .

Ligand which can ligate through two different atoms is called ambidentate ligand. ion is a ambidentate ligand. It can coordinate either through nitrogen or through oxygen to a central metal atom/ion.

The effective atomic number for
(atomic no. of ) is .
Because rhodium is in oxidation state



electrons from ligands
electrons.

This molecule is square planar, having two ammonia ligands (or two (ligands) adjacent to one another or opposite to one another as

According to recommendations of IUPAC of , there should be add iodo in the end while naming
and ions.

IUPAC name is tetraammmediaquacobalt chloride

has square planar geometry with hybridisation
The order of energies of -orbitals in square planar geometry is:

Structure of

In a weak field ligand, pairing does not take place
So,

Thus, geometry is tetrahedral with two unpaired electrons
Magnetic moment

The elements in the and transition series (the and elements) have large splitting than those in series. So, the order of is

Answer (a)

Elements of and series are more prone to spin pairing therefore they from low spin complexes

Step 1: Understanding Geometrical Isomerism
Geometrical isomerism occurs when there are different spatial arrangements of ligands around a central metal ion.
This is usually observed in square planar and octahedral complexes.
Step 2: Analyzing the Options
In option (a) [MXL ], a square planar complex with three identical ligands and one different ligand can show cis-trans isomerism, which is geometrical isomerism.

In option (b) [MX L ], a square planar complex with two identical ligands and two other identical ligands can show

Step 1: Understanding Werner's Theory
In Werner’s theory of coordination compounds, he proposed the terms primary valence and secondary valence.

The primary valence refers to the oxidation state of the metal ion.
The secondary valence refers to the number of groups (ligands) directly bound to the metal ion in a coordination complex.

Step 2: Explanation of Other Options
Option (a) Primary valence is incorrect because it refers to the oxidation number, not the number of ligands attached to the metal.

Option (c) Oxidation number is incorrect because it refers to the charge of the metal ion, not the number of ligand bonds.

Option (d) Polyhedra refers to the shape of the coordination complex, not the number of ligands bound to the metal.

Step 3: Conclusion
Thus, the term proposed by Werner for the number of groups bound directly to the metal ion is secondary valence.