transition elements colours Flashcards
What is colour change during ligand substitution of Cu2+
[Cu(H20)6] = blue to
[CuCl4]2- = yellow to
[Cu(NH3)4(H20)2]2- = deep blue
What is colour change and eqtn of redox reactions Fe2+ and Fe3+
Fe2+ = green and + MnO4- in acidic conditions = Fe3+
Fe3+ = orange brown + I- = Fe2+
What is redox reaction of Cr2O7 2- and Cr3+ and Cr2+
Cr2O72- + acidic conditions reduction in acidic conditions to Cr3+ and Cr2+
Cr3+ oxidised to Cr2O72- by H2O2 and alkaline conditions
- Cr3+ to CrO42- then Cr2O72-
What is redox of Cu2+ to Cu+ and Cu
Cu2+ and Zinc = Cu
Cu+ = Cu and Cu2+ by disproportionation
NaOH reactions
What is the violet solution formed with NaOH?
[Cr(H₂O)₆]³⁺
What is the green solution formed with NaOH?
[Fe(H₂O)₆]²⁺
What is the yellow solution formed with NaOH?
[Fe(H₂O)₆]³⁺
What is the pale pink solution formed with NaOH?
[Mn(H₂O)₆]²⁺
What is the blue solution formed with NaOH?
[Cu(H₂O)₆]²⁺
What is the green precipitate formed with NaOH?
Cr(OH)₃(H₂O)₃
What is the green precipitate formed with NaOH?
Fe(OH)₂(H₂O)₄
What is the brown precipitate formed with NaOH?
Fe(OH)₃(H₂O)₃
What is the pale brown precipitate formed with NaOH?
Mn(OH)₂(H₂O)₄
What is the blue precipitate formed with NaOH?
Cu(OH)₂(H₂O)₄
What happens when excess OH- is added to Cr?
[Cr(OH)₆]³⁻
What happens when excess OH- is added to Fe²⁺?
No change
What happens when excess OH- is added to Fe³⁺?
No change
What happens when excess OH- is added to Mn²⁺?
No change
What happens when excess OH- is added to Cu²⁺?
No change
How can you remember the formulas of the precipitates?
The number of OH- substituted is the same as the value of the charge on the initial ion.
What is the color of the solution for [Cr(H2O)6]3+?
Violet solution
What is the color of the solution for [Fe(H2O)6]2+?
Green solution
