Chemistry
Coordination Chemistry
325 Questions
Coordination chemistry focuses on coordination compounds, their structures, and their magnetic properties. The questions cover primary and secondary valencies, ligand types, and geometries of complexes. This topic is heavily tested in chemistry competitive exams and requires a good grasp of molecular structures.
primary and secondary valencycomplex geometriesligand field theorymagnetic properties of complexesisomerism in complexes
Coordination Chemistry Questions
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Only 1
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Only 2
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Only 3
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Both 1 and 2
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Both 2 and 3
A
Correct answer
Explanation
Coordination number of iron in cytochrome complex is 6. So, this is the correct answer.
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Only 1 and 3
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Only 2 and 4
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Only 1 and 2
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Only 2 and 3
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Only 3 and 4
A
Correct answer
Explanation
This option is correct because in the complexes [Fe(H2O)6]2+ and [CrF6]3-, the water and halogen are low field ligands, so both of them forms high spin complexes.
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[Co(en)3]3+
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[Co(H2O)6]3+
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[Co(CN)6]3-
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[Co(NH3)6]3+
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[CoCl6]3-
C
Correct answer
Explanation
This option is correct because CN- is one of the strongest field ligands. Crystal field splitting will be highest in [Co(CN)6]3-.
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Central metal atoms/ions in coordination complexes are Lewis acids.
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The secondary valency represents oxidation number of the central metal ion.
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Ligands are Lewis bases.
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Coordination number of cobalt in the compound [Co(ox)3]3- is 6.
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Oxidation number of cobalt in complex ion [CoCl2(en)2]+ is +3
B
Correct answer
Explanation
The secondary valency represents coordination number of the central metal ion.
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[PtCl4]2- and [ZnCl4]2-
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[Ni(CN)4]2- and [CoCl4]2-
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[ZnCl4]2- and [Ni(CN)4]2-
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[CoCl4]2- and [PtCl4]2-
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[PtCl4]2- and [Ni(CN)4]2-
E
Correct answer
Explanation
The d8 ions form square planar complexes with strong field ligands. For example [Ni(CN)4]2- .
All the complexes of Pt(II) and Au(II) are square planar. For example [PtCl4]2-
Thus, this option is correct.
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Only 1
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Only 2
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Only 3
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Only 2 and 3
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All of these
B
Correct answer
Explanation
- The complex has a square planar shape.
- CN- is a strong-field ligand.
- The d electron configuration for Ni2+ is d8.
- The splitting energy is large.
Therefore, the complex is low spin.
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Only 1 and 2
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Only 2 and 3
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Only 1 and 3
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Only 3
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All of these
D
Correct answer
Explanation
- The complex has an octahedral shape.
- F is a weak-field ligand.
- The d electron configuration for Fe3+ is d5.
- The splitting energy is small.
- Inner d orbitals will take part in hybridisation (sp3d2 hybridisation).
Therefore, the complex is outer orbital complex.
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[Fe(SCN)6]-4 and [Fe(SCN)6]-3
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[Zn(H2O)6]+2 and [Pt(Cl)4]-2
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[Ni(CN)4]-2 and Co(NH3)6]+2
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[Cr(NH3)6]+3 and [Co(NH3)6]+3
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[Co(H2O)6]+3 and [Fe(H2O)6]+2
E
Correct answer
Explanation
This option is correct because both the complexes have 4 unpaired electrons and both of these have maximum magnetic moment among all options.
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CO, N2, O2, NO+
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CO, N2, O2+, CN-
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CO, F2, NO+, CN-
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CO, N2, NO+, CN-
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CO, N2+, NO+, CN-
D
Correct answer
Explanation
Isoelectronic species have the same number of electrons: CO, N2, NO+ and CN- have 14 electrons each.
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[NiCl4]2-
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[Ni(CN)4]2-
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Cis-platin
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Carboplatin
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Zeise’s salt
A
Correct answer
Explanation
In case of tetrahedral configuration, the compound would have a magnetic moment corresponding to two unpaired electrons. [NiCl4]2- has two unpaired electrons and a tetrahedral geometry.
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Wilkinson’s catalyst - Ph3RhCl/Et3Al
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Lindlar catalyst - PtO2
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Lazier’s catalyst - Cu2Cr2O5
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Vaska's complex - IrCl(CO)(PPh3)2
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Adkins catalyst - Cr/CuO
B
Correct answer
Explanation
Lindlar catalyst is the combination of Pd/CaCO3/PbO. PtO2 is the Adam’s catalyst.
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Ring forming ligands
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Number of monodentate ligands linked to central atom
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Ligands capable of accepting π-e- density
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Ligand & central metal ion kept in square bracket
B
Correct answer
Explanation
Co-ordination Number is the number of monodentate ligands attached to central atom/ion .
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complex ion
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double salt
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cations
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radicals
A
Correct answer
Explanation
A complex ion is an ion that contains a metal cation binded to one or more small molecules or ions (such as NH3, CN- or OH-).
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coordination sphere
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coordination polyhedron
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oxidation number
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coordination number
B
Correct answer
Explanation
The spatial arrangements of the important ligand atoms which are directly attached to the central atoms/ion definition terms a coordination polyhedron about the central atoms.
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Formula of the cation must be written first followed by anion
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In the chemical formula the central metal is written before the ligands
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Prefixes like di-, tri-, tetra-, etc. are used
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The Co-ordination sphere is written in small brackets
D
Correct answer
Explanation
The Co-ordination sphere is written in square brackets.