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

Multiple choice

Which of the following complexes is most likely to exhibit the Jahn-Teller effect?

  1. [Co(NH3)6]3+

  2. [Ni(CN)4]2-

  3. [Fe(H2O)6]3+

  4. [Cr(en)3]3+
Reveal answer Fill a bubble to check yourself
Correct answer
Explanation

The Jahn-Teller effect is most likely to occur in complexes with high-spin configurations and degenerate d-orbitals. [Cu(NH3)4]2+ has a high-spin d9 configuration and a tetragonal geometry, making it susceptible to the Jahn-Teller effect.

Multiple choice

Which of the following complexes is likely to absorb light in the visible region of the spectrum?

  1. [Co(NH3)6]3+

  2. [Ni(CN)4]2-

  3. [Fe(H2O)6]3+

  4. [Cr(en)3]3+
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Complexes that absorb light in the visible region of the spectrum typically have a small crystal field splitting energy (Δ). [Co(NH3)6]3+ has a low Δ value and is therefore likely to absorb light in the visible region.

Multiple choice

What is the term used to describe the pairing of electrons in metal ion d-orbitals?

  1. Crystal field splitting.

  2. Jahn-Teller effect.

  3. Ligand field stabilization energy.

  4. High-spin and low-spin complexes.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

High-spin and low-spin complexes refer to the different electronic configurations that metal ions can adopt in coordination complexes. High-spin complexes have all the d-orbitals singly occupied, while low-spin complexes have some of the d-orbitals paired.

Multiple choice

Which of the following factors favors the formation of low-spin complexes?

  1. Strong field ligands.

  2. Weak field ligands.

  3. High oxidation states of the metal ion.

  4. Low oxidation states of the metal ion.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Strong field ligands promote the pairing of electrons in metal ion d-orbitals, leading to the formation of low-spin complexes. This is because strong field ligands cause a large crystal field splitting energy (Δ), which makes it energetically favorable for electrons to pair up.

Multiple choice

What is the term used to describe the energy difference between the high-spin and low-spin states of a coordination complex?

  1. Crystal field splitting energy.

  2. Jahn-Teller effect.

  3. Ligand field stabilization energy.

  4. High-spin and low-spin complexes.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Ligand field stabilization energy (LFSE) is the energy difference between the high-spin and low-spin states of a coordination complex. LFSE arises from the pairing of electrons in metal ion d-orbitals, which is favored by strong field ligands.

Multiple choice

Which of the following complexes is likely to have the largest ligand field stabilization energy?

  1. [Co(NH3)6]3+

  2. [Ni(CN)4]2-

  3. [Fe(H2O)6]3+

  4. [Cr(en)3]3+
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Ligand field stabilization energy (LFSE) is influenced by the strength of the crystal field. [Ni(CN)4]2- has a strong crystal field due to the strong field cyanide ligands, resulting in a large LFSE.

Multiple choice

Which of the following complexes is likely to exhibit charge transfer?

  1. [Co(NH3)6]3+

  2. [Ni(CN)4]2-

  3. [Fe(H2O)6]3+

  4. [Cr(en)3]3+
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Charge transfer is more likely to occur in complexes where the metal ion and ligands have different electronegativities. [Fe(H2O)6]3+ has a high electronegative metal ion (Fe3+) and low electronegative ligands (H2O), making it susceptible to charge transfer.

Multiple choice

What is the term used to describe the interaction between metal ions and ligands in a coordination complex?

  1. Crystal field splitting.

  2. Jahn-Teller effect.

  3. Ligand field stabilization energy.

  4. Metal-ligand bonding.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Metal-ligand bonding refers to the interactions between metal ions and ligands in a coordination complex. These interactions can be classified into various types, such as ionic bonding, covalent bonding, and coordinate bonding.

Multiple choice

Which of the following is an example of a transition metal complex?

  1. Sodium chloride

  2. Iron(III) chloride

  3. Water

  4. Carbon dioxide
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

A transition metal complex is a compound that contains a transition metal ion surrounded by ligands. Iron(III) chloride is an example of a transition metal complex because it contains an iron(III) ion surrounded by chloride ligands.

Multiple choice

What is the name of the process by which transition metals can form multiple bonds with other atoms?

  1. Hybridization

  2. Complexation

  3. Oxidation

  4. Reduction
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Hybridization is the process by which transition metals can form multiple bonds with other atoms.