potassium carbonate, chemical compound, K2CO3, white, crystalline, deliquescent substance that forms a strongly alkaline water solution. It is available commercially as a white, granular powder commonly called potash, or pearl ash. It was originally obtained from wood ashes or from the residue left in pots after certain plants, e.g., kelp, were burned in them. It is prepared commercially chiefly by electrolysis of potassium chloride to form potassium hydroxide, which is then carbonated (e.g., by adding carbon dioxide gas). It is used in the manufacture of soft soaps and glass, for washing wool, and in the production of other potassium compounds.