Transition Element Redox Reactions

Cu2+ → Cu+

Cu2+ → Cu+

Reduction
I-
Blue → Brown sol + White ppt

Cu2O → Cu + Cu2+

Disproportionation
Hot, dilute H2SO4
Brown ppt + Blue sol forms

Fe2+ → Fe3+

Oxidation
MnO4-
Purple → Colourless

Fe3+ → Fe2+

Reduction
I-
Orange-brown → Brown

Cr2O72- → Cr3+

Reduction
Zn
Orange → Green

Cr3+ → Cr2+

Reduction
Zn
Green → Blue

Cr3+ → CrO42-

Oxidation
Hot, alkaline H2O2
Green → Yellow