Potassium Hydroxide is an odorless, white or slightly yellow color compound present either in crystal or liquid form and is composed of one potassium cation and one hydroxide anion. It is a chemical inorganic compound with formula KOH and is commonly known as Caustic Potash. It is a strong base along with sodium hydroxide, lithium hydroxide and few other metal hydroxides and it also resembles with sodium hydroxide in its chemical properties and applications. It is commercially sold as translucent pellets which sticky when exposed to air as it is hygroscopic in nature. KOH dissolves readily in water and this dissolution process is exothermic and it forms a strong alkaline caustic solution.
Electrolysis of dry molten caustic potash results in the deposition of potassium metal at the cathode. KOH solutions are widely used in making soap, as an electrolyte in alkaline batteries, in electroplating, lithography and paint and varnish removers. Liquid drain cleaners also contain around 30 % of KOH. KOH solution can cause irritation when it comes in contact with skin and if its concentration is higher than 2% they become corrosive.
Commercial KOH is manufactured by the electrolysis of an aqueous solution of potassium chloride KCl or potassium carbonate in a mercury cell or membrane electrolyte cell. The co-products are chlorine and hydrogen.
Potassium hydroxide is a strong base and so it acts as a pH regulator in industrial manufacturing and processing. In the agricultural industry, KOH is used to correct the pH of acidic soils and is used to produce agricultural-grade fertilizers. These fertilizers can be used as a source of potassium for crop as potassium is the one of the major plant food. It also acts as fungicide, herbicide.
Potassium hydroxides are used in the production of various important chemicals such as potassium carbonate, potassium phosphates and organic chemicals. The potassium carbonate produced using KOH has wide application primarily in the manufacture of specialty glasses, television tubes etc.
It is a versatile cleansing agent. It is used in the production of potassium soaps, detergents, drain and pipe cleaners, shampoos, lotions, hairsprays and other cleansing products. Potassium hydroxide soaps are quite expensive as KOH is expensive compared to sodium hydroxide but it is produced in various liquid concentrations and are used in combination with sodium soaps. Potassium soaps are also referred as soft soaps.
Potassium hydroxide is used as an additive in processed foods to increase its shelf life as it acts as a stabilizer and as a thickener. It is used to wash or chemical peel the fruits and vegetables. In the processing of many products like chocolate and cocoa processing, it is applied for thickening of ice cream and even for soft drink processing. Potassium hydroxide is also used to soften olives.
Potassium hydroxide is widely employed in the medical industry to diagnose fungal infections and bacterial vaginitis. Potassium hydroxide is even used in veterinary medicine to disband calf's horns and dissolve scales and hair. It can also be used in rehydrate dried herbarium material and to dissolve warts and cuticles.