Chemistry

Coordination Chemistry

319 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

Multiple choice

Which of the following complexes shows co-ordination isomerism?

  1. [Cr (NH3)6] Cl3

  2. [Cr (NH3)6] [CO (en)3]

  3. [CO (en)2 Cl2] Cl

  4. [COCl2 (en)2] SO4
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Coordination isomerism occurs when both the cation and anion are complex ions and ligands can be exchanged between them. [Cr(NH3)6][Co(en)3] fits this definition.

Multiple choice

Cu2+ ion in the complex ion [Cu (NH3)4]2+ is

  1. sp3 hybidized

  2. dsp2 hybridized

  3. sp3 d hybridized

  4. sp3 d2 hybridized
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

[Cu(NH3)4]2+ is a square planar complex, which corresponds to dsp2 hybridization for the central copper ion.

Multiple choice

Considering Sc(III), Ti(IV), Pd(II) and Cu(II) ions, which of the following options is correct?

  1. All are paramagnetic.

  2. All are diamagnetic.

  3. Sc(III) and Ti(IV) are paramagnetic and Pd(II) and Cu(II) are diamagnetic.

  4. Sc(III) and Ti(IV) are diamagnetic while Pd(II) and Cu(II) are paramagnetic.

  5. None of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

This option is correct because the Sc(III) and Ti(IV) are diamagnetic while Pd(II) and Cu(II) are paramagnetic.

Multiple choice

Metal in each metal complex possesses

  1. primary valencies satisfied by anions only

  2. secondary valencies satisfied by the donor molecules

  3. coordination number

  4. all of these
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In coordination complexes, the central metal atom/ion exhibits primary valency (oxidation state) satisfied by anions and secondary valency (coordination number) satisfied by ligands (donor molecules). Since all these properties are characteristic of metal complexes, 'all of these' is correct.

Multiple choice

Which of the following substances shows antiferromagnetism?

  1. Fe3O4

  2. MgFe2O4

  3. MnO

  4. CrO2

  5. NaCl
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Substances like MnO showing antiferromagnetism have a domain structure similar to ferromagnetic substance, but their domains are oppositely oriented and cancel out each other's magnetic moment

Multiple choice

Which of the following is known as Pseudo Alum?

  1. KMn(SO4)2. 12H2O

  2. KCr(SO4)2. 12H2O

  3. NH4Fe(SO4)2. 12H2O

  4. FeSO4.Al2(SO4)3. 24H2O
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

  Pseudo alum has the general formula MIISO4. M2III (SO4)3. 24H2O. So on  comparing we get FeSO4.Al2(SO4)3.24H2O is pseudo alum.

Multiple choice

Which of the following statements is not true?

  1. Central metal atoms/ions in coordination complexes are Lewis acids.

  2. The secondary valency represents oxidation number of the central metal ion.

  3. Ligands are Lewis bases.

  4. Coordination number of cobalt in the compound [Co(ox)3]3- is 6.

  5. Oxidation number of cobalt in complex ion [CoCl2(en)2]+ is +3
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

The secondary valency represents coordination number of the central metal ion.

Multiple choice

Which of the following is a pair of square planar complexes?

  1. [PtCl4]2- and [ZnCl4]2-

  2. [Ni(CN)4]2- and [CoCl4]2-

  3. [ZnCl4]2- and [Ni(CN)4]2-

  4. [CoCl4]2- and [PtCl4]2-

  5. [PtCl4]2- and [Ni(CN)4]2-
Reveal answer Fill a bubble to check yourself
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.