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

In molecular ion ICl2+, the geometrical arrangement of orbital and shape are

  1. tetrahedral geometry, bent shape

  2. tetrahedral geometry, pyramidal shape

  3. trigonal bipyramidal geometry, linear shape

  4. trigonal bipyramidal geometry, bent shape

  5. tetrahedral geometry, T-shape
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

ICl2+ has sp3 hybridisation and its geometrical arrangement of orbitals is tetrahedral but the shape (according to VESPR theory) is bent due to the presence of two lone pairs. Thus, this option is correct.

Multiple choice

Which of the following statements is FALSE?

  1. Compounds of copper (II) are coloured but those of zinc (II) are colourless.

  2. Pt(IV) complexes are octahedral while Pt(II) complexes are square planar.

  3. Mn(II) ion show maximum paramagnetic character amongst bivalent ions of first transition series.

  4. Zinc metal is diamagnetic while Zn2+ ion is paramagnetic.

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

Correct answer. Zn: [Ar] 3d10 4s2 Zn2+: [Ar] 3d10 In zinc metal and Zn2+, all electrons are paired and hence they both are diamagnetic.

Multiple choice

Which of the following complexes are diamagnetic in nature? P. [CoF6]3- Q. [Fe(CN)6]4- R. Zn(H2O)6]2+ S. [Cr(H2O)6]3+

  1. Only P and Q

  2. Only P and S

  3. Only Q and R

  4. Only Q and S

  5. Only R and S
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It is incorrect. [Fe(CN)6]4- is an inner orbital complex with octahedral geometry (d2sp3 hybridisation); No unpaired electrons; diamagnetic

Zn(H2O)6]2+ is an outer orbital complex with square planar geometry (sp3d2 hybridisation); No unpaired electrons; diamagnetic

Multiple choice

Which of the following sets represents diamagnetic metal ions only?

  1. Mn3+, Fe2+, Ni2+, Zn2+

  2. Ti4+, Ni2+, Cu+, Zn2+

  3. Mn3+, Fe3+, Ni2+, Cu2+

  4. Sc3+, Fe3+, Ni2+, Cu2+

  5. Sc3+, Ti4+, Cu+, Zn2+
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Sc3+: 3d0, No unpaired electrons; diamagnetic. Ti4+: 3d0, No unpaired electrons; diamagnetic. Cu+: 3d10, 1 unpaired electron; diamagnetic. Zn2+: 3d10, No unpaired electrons; diamagnetic.

Multiple choice

Which one of the following transition metal ions is expected to form coloured complexes?

  1. Mn2+
  2. Fe3+
  3. Zn2+

Select the correct answer using codes given below:

  1. 1 and 2

  2. 1 and 3

  3. 2 and 3

  4. 1, 2 and 3

  5. None
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Mn: 3d54s2 Mn2+: 3d5 In Mn2+ d orbitals are not completely filled, so it is expected to form coloured complexes.

Fe: 3d64s2 Fe3+: 3d5 In Fe3+ d orbitals are not completely filled, so it is expected to form coloured complexes.

Multiple choice

Arrange the following central metal ions in order of increasing nephelauxetic effect.

a. Co(III) b. Ir(III) c. Fe(III)

  1. a < b < c

  2. a < c < b

  3. b < a < c

  4. c < b < a

  5. c < a < b
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The nephelauxetic effect not only depends upon the ligand type, but also upon the central metal ion. These too can be arranged in order of increasing nephelauxetic effect as follows: Mn(II) < Ni(II) ≈ Co(II) < Mo(II) < Re(IV) < Fe(III) < Ir(III) < Co(III) < Mn(IV).