11 - TEST TUBE REACTIONS FOR TRANSITION METAL IONS

• TESTING FOR Cu (2+), Co (2), Fe (2+), Fe (3+)?

  1. Add NaOH (aq)
  2. Cu (2+): pale blue precipitate (Cu(OH)2)
  3. Co (2+): pale pink precipitate (Co(OH)2)
  4. Fe (2+): green precipitate (Fe(OH)2)
  5. Fe (3+): brown precipitate (Fe(OH)3)
  6. Add excess NH3 (aq)
  7. Cu (2+): deep blue solution ([Cu(NH3)4(H2O)2] (2+))
  8. Co (2+): pale brown solution ([Co(NH3)6] (2+))
  9. Fe (2+): green precipitate (Fe(OH)2)
  10. Fe (3+): brown precipitate (Fe(OH)3)
  11. Add HCl (aq)
  12. Cu (2+): yellow solution ([CuCl4] (2-))
  13. Co (2+): blue solution ([CoCl4] (2-))
  14. Fe (2+): yellow solution (FeCl2)
  15. Fe (3+): yellow solution (FeCl4)
  16. Add Na2CO3 (aq)
  17. Cu (2+): blue-green precipitate (CuCO3)
  18. Co (2+): purple precipitate (CoCO3)
  19. Fe (2+): green precipitate (FeCO3)
  20. Fe (3+): brown precipitate and effervescence (Fe(OH)3 + CO2)