Winkler Test For Dissolved Oxygen - Analysis

Analysis

From the above stoichiometric equations, we can find that:

1 mole of O₂ → 2 moles of MnO(OH)₂ → 2 mole of I₂ → 4 mole of S₂O₃2–

Therefore, after determining the number of moles of iodine produced, we can work out the number of moles of oxygen molecules present in the original water sample. The oxygen content is usually presented as mg/dm3.