The Iodometry And Photographic processing of Sodium thiosulf

[hanlin]

In analytical chemistry, the most important use comes from the fact that the thiosulfate anion reacts stoichiometrically with iodine, reducing it to iodide as it is oxidized to tetrathionate:
2 S2O32−(aq) + I2(aq) → S4O62−(aq) + 2 I−(aq)
Due to the quantitative nature of this reaction, as well as the fact that Na2S2O3