Iodine and Sodium Thiosulfate Titration

I2 + 2Na2S2O3 → Na2S4O6 + 2NaI

Übersicht

Iodine oxidizes thiosulfate to tetrathionate while being reduced to iodide. This is the basis of iodometric titration, one of the most important analytical techniques in chemistry. Starch indicator turns blue-black with iodine and becomes colorless at the endpoint when all I₂ is consumed.

Teilnehmer

Rolle Substanz Koeffizient Zustand
Reaktant Iodine I 1 (aq)

Alltägliches Beispiel

The vitamin C content of fruit juice can be determined by iodometric titration, where ascorbic acid reduces iodine before the starch endpoint.

Industrielle Bedeutung

Iodometric titration is a standard analytical method used in water quality testing (dissolved oxygen, chlorine residual), food analysis, and pharmaceutical quality control.

Eigenschaften

Typ
Redox
Reversibel
Nein
Energie
Exotherm
ΔH
-140,0 kJ/mol

Verwandte Reaktionen

Iron(II) to Iron(III) Oxidation by Oxygen Bleaching with Sodium Hypochlorite Copper Reduction of Silver Ion Aqua Regia Dissolving Gold Cerium(IV) Reduction by Iron(II) Chlorine Oxidation of Bromide Copper Oxidation by Nitric Acid Hypochlorite Oxidation of Hydrogen Peroxide Hydrogen Peroxide as Oxidizing Agent (Acidic) Displacement of Hydrogen from Acid by Magnesium

Frequently Asked Questions

What is the equation for Iodine and Sodium Thiosulfate Titration?
The balanced equation is: I₂ + 2Na₂S₂O₃ → Na₂S₄O₆ + 2NaI.
What type of reaction is Iodine and Sodium Thiosulfate Titration?
Iodine and Sodium Thiosulfate Titration is a redox reaction.
Is Iodine and Sodium Thiosulfate Titration exothermic or endothermic?
Iodine and Sodium Thiosulfate Titration is exothermic (releases energy). The enthalpy change (ΔH) is -140.0 kJ/mol.