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Practice & Assess

Redox Titration

Determine the concentration of Fe²⁺ using potassium permanganate

Flask SolutionPale green

Volume Added0.00cm³

Switch to dropwise addition near the endpoint. Purple drops fade while Fe²⁺ is in excess; a permanent pale pink colour marks the endpoint.

Burette (0.020 M KMnO₄)

Conical Flask (25.0 cm³ Fe²⁺)

Determine the unknown Fe²⁺ concentration using standard KMnO₄. In acidic medium, permanganate acts as its own indicator.

Ionic Equation

Mn O_{4}^{-} + 5F e^{2 +} + 8 H^{+} \to M n^{2 +} + 5F e^{3 +} + 4 H_{2} O

Add 1.0 cm³ rapidly at first; switch to dropwise near the endpoint.
A permanent pale pink colour marks the endpoint; deep pink or purple means overshot.
After stopping, you will see whether you undershot, hit, or overshot the endpoint.