Identification of ions

• what is a metal ion called

  cation
• what 5 ions use the flame test

  • lithium
  • sodium
  • potassium
  • calcium
  • copper
• what flame does lithium create

  crimson flame
• what flame does sodium create

  yellow flame
• what flame does potassium create

  lilac
• what flame does calcium create

  orange-red flame
• what flame does copper create

  green flame
• sodium hydroxide solution can be used to identify some metal ions
• sodium hydroxide is added to a solution of the metal ion to be tested, a solid precipitate is formed and can be used to identify the metal ion
• aluminium, calcium and magnesium ions form white precipitates when sodium hydroxide solution is added, but only the aluminium hydroxide precipitate dissolves in excess sodium hydroxide solution.
• what colour precipitate is copper

  blue
• what colour precipitate is iron(II)

  green
• what colour precipitate is iron(III)


  brown
• what might cause some flame colours to be masked

  a sample containing a mixture of ions
• what is a flame test

  rod dipped in water and then in the compound, place in flame, observe colour
• what is a precipitate

  an insoluble solid product, produced in a liquid
• equation between calcium chloride and sodium hydroxide

  calcium chloride + sodium hydroxide -> calcium hydroxide + sodium chloride
• how do u distinguish between aluminium hydroxide and sodium hydroxide

  aluminium hydroxide would dissolve in excess sodium hydroxide