Coordination Compounds Test - 9

In Ni(CO)₄, Ni is in 0 oxidation state and its electronic configuration is 1s²2s²2p⁶3s²3d⁸3d⁸4s². CO is a strong field ligand and causes pairing of electrons and shifting of 4s electrons to 3d orbital. So hybridisation of Ni is sp³.

In given complex both H₂O and NH​​​​​_{​​​​​3} are weak field ligands and are neutral. So Ni has oxidation state +2. Its electronic configuration is 1s²2s²2p⁶3s²3p⁶3d⁸. So the number of unpaired electrons are 2.

Primary valence of the central metal atom/ion is ionisable and is satisfied by negative ions.

The splitting of degenerate d orbitals in presence of ligands in a definite geometry is called crystal field splitting. The extent of the splitting depends upon the charge on the metal ion and field of the ligand. Some ligands produce strong field and cause a large splitting whereas some ligands produce weak field and cause a small splitting.

Pt has coordination number of 4. So the given complex will have a structure [Pt(NH₃)₃Cl]Cl₃. So 3 Cl ^- ions outside the square brackets which satisfy the primary valence of the metal Pt are ionisable.

Potassium trichloro(ethylene)platinate(II) i.e. K[PtCl₃(C₂H₄)] is zeise's salt.

The crystal field theory is an electrostatic model which considers the metal-ligand bond to be ionic arising purely from electrostatic interactions between the metal ion and the ligand.

[((C₆H₅)₃P)₃RhCl] is Wilkinson catalyst, it is used in hydrogenation of alkenes.

Hardness of water is because of presence of Ca²⁺ and Mg²⁺ ions which can form stable complexes with EDTA. So by simple titration with EDTA, hardness of water can be estimated. The selective estimation of these ions can be done due to difference in the stability constants of their complexes with EDTA.

Ni forms a bright red complex with dimethylglyoxime. This reagent is used in qualitative analysis to identify Ni^{​​​​​2+} ion in a given unknown sample.