Colours Flashcards
[Co(H2O)6]2+ with Na2CO3
Pink ppt CoCO3
[Fe(H2O)6]2+
Normal: Green sol
With OH- or NH3: green ppt Fe(H2O)4(OH)2
Excess OH-: NC (remains green ppt)
Excess NH3: NC ((remains green ppt)
Chromium
- CrO42-= yellow
- Cr2O72- = Orange
[Fe(H2O)6]3+ with Na2CO3
Brown ppt Fe(H2O)3(OH)3 + CO2
[Al(H2O)6]3+
Normal: Colourless sol
With OH- or NH3: white ppt Al(H2O)3(OH)3
Excess OH-: colourless sol [Al(H2O)2(OH)4]-
Excess NH3: NC (remains white ppt)
[Fe(H2O)6]3+
Normal: Yellow sol
With OH- or NH3: brown ppt Fe(H2O)3(OH)3
Excess OH-: NC (remains brown ppt)
Excess NH3: NC (remains brown ppt)
[Cr(H2O)6]3+
Normal: Green/violet sol
With OH- or NH3: green ppt Cr(H2O)3(OH)3
Excess OH-: green sol [Cr(OH)6]3-
Excess NH3: purple sol [Cr(NH3)6]3+
[Cu(H2O)6]2+ with Na2CO3
Blue-green ppt CuCO3
Random 1
- Ni2+= green
- Cu2+= blue
- Co2+= pink
- Fe2+= pale green
- Fe3+= yellow
- Cr3+ = green/ violet
- Cr2+ = blue
Random 2
- [Co(NH3)6]2+= pale brown
- [Co(NH3)6]3+ = dark brown sol
- [CuCl4]2-= yellow-green sol
- [CoCl4]2- = blue sol
Manganese
- Mn2+= Pale pink
- MnO4- = Purple
[Cr(H2O)6]3+ with Na2CO3
Green ppt Cr(H2O)3(OH)3 + CO2
[Co(H2O)6]2+
Normal: Pink solution
With OH- or NH3: blue-green ppt Co(H2O)4(OH)2
Excess OH-: NC (remains blue-green ppt)
Excess NH3: pale brown sol [Co(NH3)6]2+
[Fe(H2O)6]2+ with Na2CO3
Green ppt FeCO3
[Al(H2O)6]3+ with Na2CO3
White ppt Al(H2O)3(OH)3 + CO2
Vanadium
- V2+ = Violet
- V3+= Green
- VO2+= Blue
- VO2+ = Yellow
[Cu(H2O)6]2+
Normal: Blue sol
With OH- or NH3: Blue ppt Cu(H2O)4(OH)2
Excess OH-: NC (remains blue ppt)
Excess NH3: Deep blue sol [Cu(NH3)4(H2O)2]2+
