Transition Metal Colours Flashcards
Cr3+ (aq)
Green solution
Mn2+ (aq)
pale pink solution
Fe2+ (aq)
Pale green solution
Fe3+ (aq)
Yellow-Brown solution
Co2+ (aq)
Pink solution
Ni2+ (aq)
Green solution
Cu2+ (aq)
Blue solution
Cr3+ (aq) + NaOH (dropwise)
Green ppt
Cr(OH)3
Mn2+ (aq) + NaOH
Pale brown ppt
Mn(OH)2
Mn2+ (aq) + NaOH and left to stand
white ppt darkens due to oxidation
MnO2
Cr3+ (aq) excess NaOH
Cr(OH)3 ppt dissolves to give clear green solution
[Cr(OH)6]3-
Fe2+(aq) + NaOH
dark green ppt
Fe(OH)2
Fe2+(aq) + NaOH and left to stand
ppt goes brown from oxidation
Fe(OH)3
Fe3+ (aq) + NaOH
brown ppt
Fe(OH)3
Co2+(aq) + NaOH
Blue ppt
Co(OH)2
Ni2+(aq) + NaOH
Green ppt
Ni(OH)2
Cu2+(aq) + NaOH
Blue ppt
Cr3+(aq) + NH3 (dropwise)
Green ppt
Cr(OH)3
Co2+(aq) + NH3 (dropwise)
Blue ppt
Co(OH)2
Cu2+(aq) + NH3 (dropwise)
Blue ppt
Cu(OH)2
Ni2+(aq) + NH3 (dropwise)
Green ppt
Ni(OH)2
Cr3+(aq) + NH3 (excess)
Dissolves green ppt to form violet solution
[Cr(NH3)6]3+
Co2+(aq) + NH3 (excess)
Dissolves blue ppt to form brown solution
[Co(NH3)6]2+
Cu2+(aq) + NH3 (excess)
Dissolves blue ppt to form deep blue solution
[Cu(NH3)6]2+
Ni2+(aq) + NH3 (excess)
Dissolves green ppt to form pale blue solution
[Ni(NH3)6]2+
Mn2+ (aq) + NH3
Pale brown ppt
Mn(OH)2
Mn2+ (aq) + NH3 and left to stand
pale brown ppt darkens
MnO2
Fe2+(aq) + NH3
Dark Green ppt
Fe(OH)2
Fe2+(aq) + NH3 and left to stand
Dark green ppt goes brown
Fe(OH)3
Fe3+(aq) + NH3
Brown ppt
Fe(OH)3
V2+ (aq)
Violet solution
V3+ (aq)
Dark Green solution
V4+ (aq)
Pale blue solution
V5+ (aq)
Yellow solution