4.4.2 Complex Ions

• What are complex ions formed by?

  Central metal ion and ligands
• The central metal ion in a complex ion accepts electron pairs from ligands
• Coordinate covalent bonds are formed between the metal ion and ligands in complex ions.
• What is the coordination number of the tetraammine copper(II) complex ion $[Cu(NH_{3})_{4}]^{2 + }$?


  4
• The geometry of the $[Cu(NH_{3})_{4}]^{2 + }$ complex ion is square planar
• What is the role of ligands in complex ions?

  Donate electron pairs
• Match the type of ligand with its electron pairs donated:

  Monodentate ↔️ One

  Bidentate ↔️ Two

  Polydentate ↔️ Three or more
• Polydentate ligands enhance the stability of complex ions.
• The coordination number in a complex ion refers to the number of coordinate bonds
• What is one factor influencing the coordination number of a complex ion?

  Metal ion size
• Bulky ligands may limit the coordination number of a complex ion.
• What is the first rule in the nomenclature of complex ions?

  Cation before anion
• Greek prefixes such as di, tri, and tetra are used to indicate the number of ligands
• The oxidation state of the metal ion in a complex ion is indicated in Roman numerals.
• What type of bond do ligands form with a central metal ion?

  Coordinate covalent
• Ligands donate one or more pairs of electrons
• Polydentate ligands enhance the stability of complex ions.
• The coordination number refers to the number of coordinate bonds
• What are two factors that influence the coordination number of a complex ion?

  Metal ion size and charge, ligand size
• Smaller metal ions prefer lower coordination numbers.
• In complex ion nomenclature, the cation is named before the anion
• What prefix is used to indicate that there are three identical ligands in a complex ion?

  Tri
• Negatively charged ligands end with the suffix '-o'.
• What is the common shape of a complex ion with a coordination number of 6?

  Octahedral
• Structural isomers have different connectivity
• Cis isomers have ligands on opposite sides of the metal ion.

  False
• What term measures the affinity of a metal ion for ligands in a complex ion?

  Equilibrium constant
• Higher charge density of the metal ion leads to greater stability
• What effect increases the stability of complex ions by forming rings with polydentate ligands?

  Chelate effect
• Complex ions are formed through coordinate covalent bonds between metal ions and ligands.
• Match the component of a complex ion with its role:

  Central Metal Ion ↔️ Accepts electron pairs from ligands

  Ligands ↔️ Donate electron pairs to the metal ion

  Coordinate Covalent Bond ↔️ Forms between metal and ligand
• In what medical application are complex ions used to remove toxic heavy metals from the body?

  Chelate therapy
• The formation of colored complexes allows for the quantification of metal ions
• Arrange the applications of complex ions in the order they are mentioned in the text:

  1️⃣ Chelate Therapy

  2️⃣ Catalysis

  3️⃣ Analytical Chemistry