Transition Elements + Qualitative Analysis

• What is a transition element?

  A d block element with partially filled d subshell
• Where are the transition metals located in the periodic table?

  In the middle block from Ti to Cu
• Which two elements in the d block are not considered transition metals?

  Scandium and zinc
• Why are scandium and zinc not considered transition metals?

  Scandium forms Sc3+ with empty d orbitals
• What is the noble gas configuration of chromium?

  [Ar]4s13d5
• What is the noble gas configuration of copper?

  [Ar]4s13d10
• Which electrons do transition metals lose first when forming ions?

  4s electrons
• What are some characteristic physical properties of transition metals?

  • Metallic
  • High density
  • High melting and boiling points
  • Shiny
  • Good conductors of heat and electricity
• What are the characteristic chemical properties of transition metals?

  1. Variable oxidation states
  2. Coloured compounds/ions in solution
  3. Good catalysts
  4. Form complex ions
• In potassium manganate (VII), what is the oxidation number of Mn?

  Mn = +7
• How do transition metals act as effective catalysts?

  • Provide a surface for reactions
  • Change oxidation states to form intermediates
• Give examples of transition metal catalysts and the processes they catalyse.

  • Iron - Haber process
  • Vanadium (V) oxide - contact process
  • Nickel - hydrogenation of alkenes
  • Manganese (IV) oxide - decomposition of hydrogen peroxide
  • Copper sulfate - hydrogen production
• What is a complex ion?

  Transition metal ion bonded to ligands
• Define a ligand.

  Molecule or ion donating electrons to metal
• What is a coordinate bond?

  A bond where one atom provides both electrons
• What does the coordination number indicate?

  Number of coordinate bonds with ligands
• What is a mono/unidentate ligand?

  A ligand forming one coordinate bond
• What is a bidentate ligand?

  A ligand forming two coordinate bonds
• What is a multidentate ligand?

  A ligand forming three or more coordinate bonds
• Give examples of common monodentate ligands.

  • Cl-
  • H2O
  • NH3
  • CN-
• What is the most common bidentate ligand?

  Ethane-1,2-diamine
• How many coordinate bonds can benzene-1,2-diol form?

  2 coordinate bonds
• How many coordinate bonds can ethanedioate form?

  2 coordinate bonds
• How many coordinate bonds does ethane-1,2-diamine form?

  2 coordinate bonds
• What is the shortened name for ethane-1,2-diamine?

  en
• How many coordinate bonds does EDTA4- form?

  Six
• What does it mean for EDTA to be a chelating agent?

  It binds metal ions to form complex ions
• What ion is formed when a transition metal compound is dissolved in water?

  Aqua ion
• What shape does an aqua ion form?

  Octahedral complex ion
• If a transition metal ion has 2 ligands, what shape is it usually?

  Linear
• If a transition metal ion has 4 ligands, what shape is it usually?

  Tetrahedral
• What is an exception to the tetrahedral shape rule for 4 ligands?

  Platinum forms square planar shape
• What shape is a complex ion if it has 6 ligands?

  Octahedral
• How can complex ions display E-Z or cis-trans isomerism?

  • Ligands differ in spatial arrangement
  • Applies to square planar and octahedral shapes
• What is the general shape of ions with 4 ligands?

  Tetrahedral
• What is an exception to the tetrahedral rule for 4 ligands?

  Platin is square planar
• What shape does a complex ion with 6 ligands have?

  Octahedral
• How can complex ions display E-Z or cis-trans isomerism?

  Ligands differ in spatial arrangement
• What shapes of ions can display E-Z or cis-trans isomerism?

  Square planar and octahedral
• What conditions are needed for optical isomerism in complex ions?

  Octahedral with 2 or more bidentate ligands