COLOURS OF INORGANIC IONS & COMPLEXES Flashcards
What is the colour of [Cu(H2O)6]2+
pale blue solution
What is the colour of Cu(OH)2 (s)?
pale blue precipitate
How is Cu(OH)2 (s) formed?
Add NH3 dropwise to Cu2+(aq)
What is the colour of [Cu(NH3)4(H2O)2]2+?
dark blue solution
How is [Cu(NH3)4(H2O)2]2+ formed?
Add excess NH3 to Cu2+(aq)
What is the colour of CuCl42-?
yellow solution
How is CuCl42- formed?
Add excess HCl to Cu2+(aq)
What is the colour of Cu+?
red
How is Cu+ formed?
Reduction of Cu2+ with I-
(Cu2+ + 3I- ⟶ CuI(s) + I2 (aq), forms white precipitate CuI and brown I2)
What colour is Cu2+/Cu?
pale blue
What colour is [CoCl4]2-?
blue solution
How is [CoCl4]2- formed?
Add excess HCl to CoCl2•6H2O
What colour is [Cr(H2O)6]3+?
pale purple solution
What colour is Cr(OH)3 (s)?
dark green precipitate
How is Cr(OH)3 (s) formed?
Add NH3 dropwise to Cr3+(aq)
What colour is [Cr(NH3)6]3+?
purple solution
How is [Cr(NH3)6]3+ formed?
Add excess NH3 to Cr3+(aq)
What colour is [Cr(OH)6]3-?
dark green solution
What colour is Cr2O72-?
orange solution
How is Cr2O72- formed?
K2Cr2O7 in 1moldm-3 H2SO4
What colour is CrO42-?
yellow solution
How is CrO42- formed?
Oxidation of Cr3+ with hot alkaline H2O2
What colour is [Mn(H2O)6]2+?
pale pink solution
What colour is Mn(OH)2 (s)?
pale brown precipitate
How is Mn(OH)2 (s) formed?
Add NaOH dropwise to Mn2+(aq)
What colour is [Fe(H2O)6]2+?
pale green solution
What colour is Fe(OH)2 (s)?
dark green precipitate
How is Fe(OH)2 (s) formed?
Add NaOH dropwise to Fe2+(aq)
What colour is [Fe(H2O)6]3+?
yellow
What colour is Fe(OH)3 (s)?
orange-brown precipitate
How is Fe(OH)3 (s) formed?
Add NaOH to Fe3+ dropwise
What is the colour change from MnO4-/Fe2+ to Mn2+/Fe3+?
purple to pale pink
What is the colour change from I-/Fe3+ to I2/Fe2+?
orange-brown to brown