Transition Metals

• what is the colour complex when NaOH is added to [Fe(H2O)6]3+?

  brown ppt
• What is the colour complex when NaOH is added to [Fe(H20)6]2+?

  Green ppt
• What is the colour complex when NaOH is added to [Cu(H20)6]2+?

  blue ppt
• What is the colour complex when little NaOH is added to [Al(H20)6]3+?

  white ppt
• What is the colour and formula of the complex when excess NaOH is added to [Al(H20)6]3+?

  colourless sol. - [Al(H20)2(OH)4]1-
• What is the colour change of the formula and complex when excess NH3 is added to [Cu(NH3)4(H2O)]2+?

  • Blue sol. -> deep blue sol.
  • Cu(NH3)4(H2O)2]2+
• What is the colour and formula when Na2CO3 is added to [Fe(H2O)6]2+?

  • FeCO3
  • Green ppt
• What is the colour and formula when Na2CO3 is added to [Cu(H2O)6]2+?

  • CuCO3
  • blue-green ppt
• What is the colour and formula when Na2CO3 is added to [Fe(H2O)6]3+?

  • Fe(H2O)3(OH)3 + CO2 + H2O
  • brown ppt
• What is the colour and formula when Na2CO3 is added to [Al(H2O)6]3+?

  • Al(H2O)3(OH)3 + CO2 +H2O
  • white ppt
• What is the colour and formula when conc. HCl is added to [Fe(H2O)6]2+?

  • [FeCl4]2-
  • yellow
• What is the colour and formula when conc. HCl is added to [Fe(H2O)6]3+?

  • [FeCl4]1-
  • yellow
• What is the colour and formula when conc. HCl is added to [Cu(H2O)6]2+?

  • [CuCl4]2-
  • Green
• What is the colour and formula when conc. HCl is added to [Al(H2O)6]3+?

  • [AlCl4]1-
  • colourless
• Why is M3+ more acidic than M2+?

  • M3+ attracts more e- density
  • O-H more polarised
  • H more readily dissociates
• What is the definition of a transition metal?

  an element with an incomplete d sub shell. They form at least one stable ion.
• What are 5 properties of transition metals?

  • for positive ions
  • form coloured complexes
  • form coloured ions
  • variable oxidation states
  • good catalysts