Qualitative analysis Flashcards
[Cu(H20)6]2+ NH3 (dropwise) → Cu(OH)2
Pale blue (Cu2+) → Blue (precipitate)
[Cu(H20)6]2+ NH3 (excess) → [Cu(NH3)4(H20)2]2+
Pale blue (Cu2+) → Dark blue
[Cu(H20)6]2+ + 4Cl- ⇌ [CuCl4]2-
Pale blue (Cu2+) ⇌ Green (mix) ⇌ Yellow
KCr(SO4)• 12(H2O) + H2O → [Cr(H20)6]3+
Colourless → Violet
Cr2(SO4)3 + H2O → [Cr(H20)5SO4]+
Colourless → Green
[Cr(H20)6]3+ + NH3 (dropwise) → Cr(OH)3
Violet → Grey-Green (precipitate)
[Cr(H20)6]3+ + NH3 (excess) → [Cr(NH3)6]3+
Violet → Purple
Cu2+ + 2OH- → Cu(OH)2
Pale Blue → Blue (Precipitate)
Fe2+ + 2OH- → Fe(OH)2
Pale green → Green (precipitate)
(in air) Fe(OH)2 → Fe(OH)3
Green (precipitate) → Orange-Brown (precipitate)
Fe3+ + 3OH- → Fe(OH)3
Pale yellow → Orange-Brown (precipitate)
Mn2+ + 2OH- → Mn(OH)2
Pale Pink → Light Brown (precipitate)
Cr3+ + 3OH- → Cr(OH)3
Violet → Grey-Green (precipitate)
Cr(OH)3 + 3OH- → [Cr(OH)6]3-
Grey-Green (precipitate) → Dark Green
2Fe3+ 2I- → 2Fe2+ + I2
Orange-Brown (Fe3+) → Pale Green (Fe2+) + Brown (I2) so unclear