One of the oldest methods used to prepare potassium hydroxide is the method that relies on boiling potassium carbonate solution with calcium hydroxide (quicklime), where the reaction occurs instead of precipitating calcium carbonate leaving potassium hydroxide in the solution. .
Potassium hydroxide is highly soluble in water that expels an amount of heat. It is alkaline that appears in the form of white granules or scales that do not tolerate temperature and the appearance of purple.
Potassium hydroxide is expensive so it is recommended to use sodium hydroxide in industry as it is very cheap.