Potassium Hydroxide

Products

Potassium hydroxide is available as a pure substance and in the form of solutions in pharmacies and drugstores. It is also found in medical devices and has similar properties to sodium hydroxide (NaOH).

Structure and properties

Pure potassium hydroxide (KOH, M_r = 56.11 g/mol) exists as a white, hard, odorless, crystalline mass in the form of rods, cookies, beads, or irregular pieces. It is hygroscopic and deliquesces in air, absorbing carbon dioxide. Potassium hydroxide is very soluble in water. The solutions are called potassium hydroxide solutions. Structure: K⁺OH^–

Effects

Potassium hydroxide has corrosive properties and is a strong base. It is used in the manufacture of potassium soaps and other soft soaps, among other things. KOH leads to ester hydrolysis of triglycerides of fats and fatty oils because it reacts with hydroxide ion (OH^–) is a strong nucleophile:

• Triglyceride + 3 KOH 3 fatty acids as potassium salt + glycerol.

Amides can also be hydrolyzed with potassium hydroxide. With carbon dioxide from the air, potassium hydroxide forms potassium carbonate (K₂CO₃).

Areas of application

In the form of suitable preparations and concentrations:

• For the preparation of a potash soap (medicinal soft soap) and other soft soaps.
• For the treatment of dell warts.
• As a reagent, for chemical syntheses.
• As a diagnostic agent, for example, for nail fungus.
• As a food additive, for example, as an acidity regulator.
• As a cleaning agent, for example, as a drain cleaner and for ovens.

Preparation of the solution

The solution in water is exothermic, which means that a lot of heat is released. When preparing solutions, the water should be measured first and then carefully add the potassium hydroxide, preferably in a fume hood behind protective glass (chapel).

Adverse effects

Potassium hydroxide is corrosive and can cause severe burns (chemical burns) to the skin, mucous membranes and eyes if used improperly. It must not be touched, drunk, inhaled or ingested directly. It is essential to observe the precautions in the safety data sheet (e.g. gloves, face protection, respiratory protection, protective goggles, work clothing).