Unknown substance X

Unknown substance X

1. Cation

   • Coloured Compounds
     • Aqueous sodium hydroxide/Aqueous ammonia
       • Red-brown ppt (Insoluble in Excess)
         • Iron (III) [Fe ]
       • Green ppt (Insoluble in Excess)
         • Iron (II) [Fe ]
       • Light blue ppt
         • Aqueous ammonia: Soluble in excess giving a dark blue solution ; Aqueous sodium hydroxide: Insoluble in excess
           • Copper (II) [Cu ]
   • Colourless solution/white solid
     • Aqueous sodium hydroxide
       • Ammonia produced on warming
         • Ammonium [NH ]
       • Insoluble
         • White ppt
           • Soluble in excess giving a colourless solution
             • Zinc [Zn ]
             • Lead (II) [Pb ]
             • Aluminium [Al ]
           • Insoluble in excess
             • Calcium [Ca ]
     • Aqueous ammonia
       • Soluble
         • Calcium [Ca ]
       • Insoluble
         • White ppt
           • Soluble in excess giving a colourless solution
             • Zinc [Zn ]
           • Insoluble in excess
             • Lead (II) [Pb ]
             • Aluminium [Al ]
     • Test for cations
       • No ppt
         • Flame Test
           • Orange flame
             • Sodium [Na ]
           • Lilac flame
             • Potassium [K ]
           • Brick-red flame
             • Lithium [Li ]
           • Blue-green flame
             • Copper (II) [Cu ]
           • Red (Reddish-violet) flame
             • Rubidium [Rb ]
           • Pale-green flame
             • Barium [Ba ]
         • Acid Test (add Magnesium ribbon)
           • Hydrogen Gas [H ]

2. Anion

   • Acidify with dilute nitric acid
     • Aqueous barium nitrate/barium chloride
       • White ppt
         • Sulfate [SO ]
     • Aqueous silver nitrate
       • Yellow ppt
         • Iodide [I ]
     • Aqueous silver nitrate/Aqueous lead (II) nitrate
       • White ppt
         • Chloride [Cl ]
   • Dilute acid
     • Effervescence, CO2 produced
       • Carbonate [CO ]
   • Aqueous sodium hydroxide + Aluminium foil, warm carefully
     • Ammonia produced
       • Nitrate [NO ]

3. Gas

   • Chlorine [Cl ]
     • Turns damp blue litmus paper red and bleaches it
   • Sulfur dioxide [SO ]
     • Decolourises acidified potassium permanganate (VII) [turns from purple to colourless]/ Acidified potassium dichromate (VI) changes from orange to green
   • Carbon dioxide [CO ]
     • White ppt in limewater [CaCO3], soluble in excess to form colourless solution [CaHCO3]
   • Oxygen [O ]
     • Relights glowing splint
   • Hydrogen [H ]
     • extinguishes a lighted splint with a "pop" sound
   • Ammonia [NH ]
     • Turns damp red litmus paper blue