Volumetric Determination of Bromate

Potassium bromate in the purest commercial product is 99% pure. When the powder is dried at 120°C for 2 hours can be used as a primary standard, llie solution can be titrated after oxidising iodide to iodine as above. 

Prepare a M/60 solution of potassium bromate. Pipette 25.0 cm into a 250 cm conical flask. Acidify liberally with HCl, add 2 g KI and titrate the liberated iodine as above. 

After reducing a chlorate solution with iron(II) sulphate, the chloride formed is precipitated and weighed as AgCl. 

Since ICi forms a stable complex in HCI solution (ICI+Cf 5.ICl2 ), the overall half cell reaction may be written  

Under these conditions, KIO3 acts as a powerful oxidant (E°=1.23 V). Oxidation by KIO3 proceeds through the stages  

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