Group IIB

• What are the principal metals in Group IIB (Volatile Group)?


  • Zinc (30)
  • Cadmium (40)
  • Mercury (80)
• What distinguishes Group IIB metals from other transition elements?


  They have a filled set of d-orbitals.
• What is unique about mercury in Group IIB?


  It exists as a liquid at room temperature.
• What is mercury commonly referred to as?


  Quicksilver.
• What happens to Group IIB metals when exposed to air?


  They form an adherent oxide or basic carbonate coating.
• Why is zinc used in alloys?


  Because it forms an adherent oxide coating that prevents further oxidation.
• How are zinc and cadmium classified in terms of metal type?


  They are classified as base metals.
• What is the basicity of the oxides and hydroxides of Group IIB metals?


  They are weak bases.
• How does the strength of basicity change in Group IIB metals?


  It increases going down the group.
• What is the electron configuration of Group IIB metals?


  They have a pseudo-inert gas configuration.
• What ions do zinc and cadmium typically form?


  They typically form divalent ions.
• What unique property does mercury have regarding ion formation?


  It can form a monovalent ion (Hg₂²⁺).
• How do zinc and cadmium behave in terms of complex formation?


  • They readily form complexes such as ammonia and cyano complexes.
  • Mercury does not easily form complexes.
• What are the identity tests for zinc (Zn²⁺)?


  • H₂S: White precipitate of ZnS.
  • K₄Fe(CN)₆: White precipitate of K₂Zn₃[Fe(CN)₆]₂.
  • NH₃: White precipitate of Zn(OH)₂, soluble in excess.
  • NaOH: White precipitate of Zn(OH)₂, soluble in excess.
• What are the identity tests for cadmium (Cd²⁺)?


  • H₂S: Yellow precipitate of CdS, insoluble in Na₂S.
  • K₄Fe(CN)₆: White precipitate of Cd₂Fe(CN)₆.
  • NH₃: White precipitate of Cd(NH₃)₄.
• What are the identity tests for mercury (Hg²⁺)?


  • HCl: White precipitate of Hg₂Cl₂, which blackens with NH₃.
  • KI: Green precipitate of Hg₂I₂, soluble in excess.
  • H₂S: Black precipitate of HgS, soluble in excess.