Chemistry - Redox Reactions and Titrations

State is (aq) unless otherwise stated

MnO₄^- + 8H⁺ + 5Fe²⁺ → Mn²⁺ + 5Fe³⁺ +4H₂O

Purple to colourless (pale pink solution from burette)

2Fe³⁺ +2I^- → 2Fe²⁺ + I₂

Colourless to brown (brown solution from iodide)

Cr₂O₇^2- +14H⁺ + 3Zn → 2Cr³⁺ +3Zn²⁺ +7H₂0 (l)

2Cr³⁺ + Zn (s) → 2Cr⁺ + Zn²⁺

Orange to Green to Blue

2Cr³⁺ + 3H₂0₂ + 10OH^- → 2CrO₄^2- + 8H₂O

Green to Yellow (yellow solution from chromate)

2Cu²⁺ + 4I^- → 2CuI +I₂

Pale blue solution to brown solution with white precipitate

Cu₂O + H₂SO₄ → Cu + CuSO₄ + H₂O

White solution to pale blue solution with brown precipitate

2S₂O₃^2- + I₂ →

2I^-+ S₄O₆^2-

Colour change at end point for iodine-thiosulphate titration

(addition of iodine) blue black to colourless

Colour change at end point of iron-manganate

Colourless to pale pink (due to MnO₄^- to Mn²⁺)