Potassium Chlorate from Bleach and Salt Substitute

How to Make Potassium Chlorate from Household Chemicals

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Potassium chlorate is an important potassium compound that can be used as an oxidizer, disinfectant, source of oxygen, and component in pyrotechnics and chemistry demonstrations. You can make potassium chlorate from common household bleach and salt substitute. The reaction is not particularly efficient, but it's something to keep in mind if you need potassium chlorate right away or just want to know how to make it.

Materials for Making Potassium Chlorate

  • chlorine bleach
  • potassium chloride (sold as a salt substitute)
  • filter paper or coffee filter

Prepare Potassium Chlorate

  1. Boil a large volume (at least a half liter) of chlorine bleach, just until crystals start to form. Do this outdoors or under a fume hood, to avoid inhaling the vapor. Boiling bleach disproportionates sodium hypochlorite into sodium chloride and sodium chlorate.

    3 NaClO → 2NaCl + NaClO3

  2. As soon as crystals start to form, remove the bleach from heat and allow it to cool.
  3. In a separate container, prepare a saturated solution of potassium chloride by stirring potassium chloride into the water until no more will dissolve.
  4. Mix equal volumes of the boiled bleach solution and potassium chloride solution, taking care to keep solids from either solution out of the mixture. Potassium chlorate will precipitate out, leaving sodium chloride in solution.

    KCl + NaClO3 → NaCl + KClO3

  1. Cool the solution in the freezer to increase the potassium chlorate yield.
  2. Filter the mixture through filter paper or a coffee filter. Keep the solid potassium chloride; discard the sodium chloride solution.
  3. Allow the potassium chlorate to dry before storing or using it. NurdRage has a video of the process if you'd prefer to see how it's done.

    You can test the potassium chlorate in a simple chemistry demonstration: