Iodine and Sodium Thiosulfate Titration
I2 + 2Na2S2O3 → Na2S4O6 + 2NaI
Aperçu
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.
Participants
| Rôle | Substance | Coefficient | État |
|---|---|---|---|
| Réactif | Iodine I | 1 | (aq) |
Exemple du quotidien
The vitamin C content of fruit juice can be determined by iodometric titration, where ascorbic acid reduces iodine before the starch endpoint.
Importance industrielle
Iodometric titration is a standard analytical method used in water quality testing (dissolved oxygen, chlorine residual), food analysis, and pharmaceutical quality control.
Propriétés
- Type
- Redox
- Réversible
- Non
- Énergie
- Exothermique
- ΔH
- -140,0 kJ/mol
Réactions associées
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)
Copper Oxidation by Nitric Acid
Hypochlorite Oxidation of Hydrogen Peroxide
Hydrogen Peroxide as Oxidizing Agent (Acidic)
Hydrogen Peroxide Disproportionation
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.