What is metal ligand ratio?
An alternative to the method of continuous variations for determining the stoichiometry of metal-ligand complexes is the mole-ratio method in which the amount of one reactant, usually the moles of metal, is held constant, while the amount of the other reactant is varied.
How does the nature of ligand affect the stability of the complex?
Ligands having vacant p- or d-orbital tend to form π bond and hence form stable complexes with metals. Ligands that are capable of forming such π bond are CO, CN−, alkene, phenanthroline, etc.
How does the nature of central metal ion determine the stability of complexes?
Conclusively, the greater is the positive charge density on the central metal ion, greater will be the electronegativity and consequently greater stability of the complexes.
Which complex is more stable?
Chelate complexes are more stable than the analogous complexes with monodentate ligands.
How is metal ligand ratio determined by Spectrophotometrically?
The absorbance of each solution is measured and plotted against the mole fraction of the ligand. The extrapolation of the tangents of the two parts of the curve intersects at a point which gives the mole fraction of the ligand in the complex. The method can be also applied using the mole fraction of the metal.
Which of the following ligands form more stable complex?
[Co(en)3]+3 is the most stable complex as en is a bidentate ligand which forms three member ring with metal. So, stability is due to chelation.
What is the nature of ligands in complex compound?
In complex compounds, ligands are Lewis bases while central metal ions are Lewis acids.
On what factors the stability of complex ion depends?
The stability of a complex depend upon the nature of the central metal ion as: (i) Charge on the central metal ion: In general, the greater the charge density on the central ion, the greater is the stability of its complexes.
Which of the following ligand will form the most stable complex with a metal?
Complete answer: Among all the complexes, ${K_2}\left[ {Ni\left( {EDTA} \right)} \right]$ is the most stable complex because it consists of a hexadentate ligand and as we know hexadentate ligand is a ligand which coordinate with central metal ion through six donor atoms are known as hexadentate ligands.
How do you determine the stability of a complex?
The most important characteristics of the central atom, determining the stability of the complex compound, are the degree of oxidation (charge on the central ion in the case of ionic complexes), the dimensions, and the electronic structure.
What is the mole ratio method?
ABSTRACT. In the molar ratio method, a property of a solution is plotted against the molar ratio of the two reactants, the concentration of one being kept constant. The stoichiometry of the complex or complexes formed is deduced from the position of breaks in the curve.
What is the difference between mole ratio method and Job’s method?
The key difference between Job’s method and mole ratio method is that in Job’s method, the molar concentrations of reactants are held a constant, while in mole ratio method, the molar concentration of a reactant is kept constant and the molar concentration of other reactants varies.
Why are metal EDTA complexes highly stable?
EDTA-metal ligand complex The two nitrogen atoms each have a lone electron pair too and form a coordination bond with Zn2+. The complexes formed are very strong because they form stable five-membered rings, i.e. chelates.
What is the nature of the metal in complex compound is?
● Explanation – Complex compounds are substances in which a central metal atom is surrounded by nonmetal atoms/groups (ligands). Formation of complex compounds is explained by Lewis acid / base theory. In complex compounds, ligands are Lewis bases while central metal ions are Lewis acids.
How do ligands form complexes with transition metals?
According to this model, transition-metal ions form coordination complexes because they have empty valence-shell orbitals that can accept pairs of electrons from a Lewis base. Ligands must therefore be Lewis bases: They must contain at least one pair of nonbonding electrons that can be donated to a metal ion.
Which increases stability of complex ion?
(iii) Presence of chelate rings: Formation of chelate rings increases the stability of the complex.
Which ligand is more stable?
Polydentate ligands form more stable complex than unidentate ligand. If multidentate ligand is cyclic, it further increases the stability, it is called macrocyclic effect.
Which among the metal ion is more stable?
The smaller the size of the metal ion, the more stable with the metal complexes.
How does the central metal ion affect the stability of complex?
iv) Electronegativity: Electronegativity of the central ion also influences the stability of its complexes. This is because the bonding between a central ion and ligand is due to the donation of electron pairs by the ligands. Hence, a strongly electron-attracting central ion will give stable complexes.