Making potassium iodide from elemental iodine and potassium hydroxide
name: Potassium hydroxide and potassium iodide form the iodine
Make Potassium iodide from Iodine.
Iodide iodine reacting with the KOH solution
by phim MY
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3 I2 + 6 KOH → 5 KI + KIO3 + 3 H2O
- Pour some water into a flask and dissolve some potassium hydroxide in it.
- Put iodine crystals into the flask and heat it with a burner. All iodine should dissolve and react with potassium hydroxide. If the solution becomes brown there is an excess of iodine. In this case just add more potassium hydroxide.
- Cool the flask down. Potassium iodate precipitates in the cold solution.
- Filter potassium iodate.
- Boil a little bit of the filtered solution and repeat the precipitating of potassium iodate.
Iodine reacts with potassium hydroxide forming potassium iodide (KI) and potassium iodate (KIO3). This is the disproportionation reaction.
Because potassium iodate is much less soluble in water than potassium iodide it is possible to separate these two substances using the precipitation of potassium iodate from the solution.