3.2.5.2 Complex Formation

• The central metal ion in a coordination complex acts as a Lewis acid
• The suffix '-o' is added to the names of anionic ligands
• Match the rule of naming coordination complexes with its description:

  Ligands Named First ↔️ Name ligands in alphabetical order before the metal

  Anionic Ligands ↔️ Add '-o' to the end of anionic ligand names

  Metal Oxidation State ↔️ Indicate oxidation state in parentheses using Roman numerals

  Complex Ion Charge ↔️ Indicate overall complex ion charge in square brackets
• What are the three main types of ligands based on the number of electron pairs they donate?

  Monodentate, bidentate, polydentate
• The coordination number of a coordination complex refers to the number of ligands bonded to the central metal ion.
• The coordination geometry is determined by the number of ligands and the need to minimize electron pair repulsion.
• A coordination complex is formed when a central metal ion is surrounded by ligands
• Match the ligand example with its chemical formula:

  Water ↔️ H2O

  Ammonia ↔️ NH3

  Chloride ↔️ Cl-

  Cyanide ↔️ CN-
• The term 'chloro' is used for an anionic ligand in coordination complex nomenclature.


  True
• Ethylenediamine is an example of a bidentate ligand.

  True
• Coordination complexes are compounds with a central metal ion surrounded by ligands.

  True
• Steps in naming coordination complexes:

  1️⃣ Name ligands in alphabetical order

  2️⃣ Add '-o' to anionic ligands

  3️⃣ Indicate metal oxidation state in parentheses

  4️⃣ Indicate overall complex ion charge in brackets
• What is the name of the complex `[Cr(H2O)4Cl2]Cl`?

  Tetraaquodichlorochromium(III) chloride
• The oxidation state of chromium in `[Cr(H2O)4Cl2]Cl` is (III).

  True
• Monodentate ligands donate only one electron pair to the metal ion.


  True
• What is the coordination geometry of `[Ni(CO)4]`?

  Tetrahedral
• The coordination geometry of a coordination complex describes the spatial arrangement of ligands around the central metal ion.
• What is the stability constant (K) used to quantify in coordination equilibria?

  Stability of coordination complexes
• What factors increase the stability of coordination complexes?

  Higher metal charge, smaller metal size
• What is a coordination complex formed from?

  Central metal ion and ligands
• Match the coordination complex example with its ligand:

  [Cu(H2O)6]2+ ↔️ H2O

  [Co(NH3)6]3+ ↔️ NH3
• The oxidation state of the metal in a coordination complex is indicated using Roman numerals.


  True
• When naming anionic ligands, the suffix '-o' is added to their names
• Match the type of ligand with its definition and example:

  Monodentate ↔️ Ligands that donate one electron pair | Water (H2O)

  Bidentate ↔️ Ligands that donate two electron pairs | Ethylenediamine (en)

  Polydentate ↔️ Ligands that donate more than two electron pairs | EDTA
• Common coordination numbers include 4, 6, and 8.

  True
• The coordination number of a coordination complex can only be 4 or 6.

  False
• What is the role of ligands in a coordination complex?

  Donate electron pairs
• In what areas are coordination complexes important?

  Catalysis, biology, materials science
• How are ligands classified based on the number of electron pairs they donate?

  Monodentate, bidentate, polydentate
• What is an example of a polydentate ligand?

  EDTA
• A coordination number of 4 often results in a tetrahedral geometry.

  True
• Higher stability constants indicate more stable coordination complexes.


  True
• Polydentate ligands provide greater stability to coordination complexes than monodentate ligands.


  True
• What is a coordination complex formed from?

  A central metal ion and ligands
• The central metal ion in a coordination complex acts as a Lewis acid.

  True
• Arrange the steps for naming coordination complexes according to IUPAC rules:

  1️⃣ Ligands named first in alphabetical order

  2️⃣ Anionic ligands end in '-o'

  3️⃣ Metal oxidation state in parentheses

  4️⃣ Complex ion charge indicated in brackets
• Monodentate ligands donate one electron pair to the metal ion.
• What does the coordination number of a coordination complex represent?

  Number of ligands bonded
• Match the coordination number with its corresponding geometry:

  4 ↔️ Square planar

  6 ↔️ Octahedral
• The stability constant for [Cu(NH3)4]²⁺ is 10¹².