WHAT IS POTASSIUM HYDROXIDE?

Potassium Hydroxide (KOH) is an inorganic chemical compound commonly referred to as lye is a strong base. It is also called caustic potash. It has a substantial chemical and industrial role. Due to its alkaline nature, it is marketed in several forms like flakes, powder, and even pellets. It has an appearance of a clear solution in its aqueous form. It is slightly soluble in ether but freely soluble in water and glycerin. Although it is not combustible, it is highly incisive and corrosive.

Physical Properties

Its appearance is yellow to white flakes, fused masses, and crystalline powder. It has a rhombohedral structure. It is soluble in ethanol and methanol.  On decomposing, it breaks down into potassium oxide. Potassium oxide is toxic to contact with skin and eyes (irritation and burn). It is an odourless solid. It is a potent base.

Uses of Potassium Hydroxide

• It is used as an electrolyte in alkaline batteries as its solution is more conductive.
• It serves in the thickening of food and lithography.
• It is used in electroplating.
• It is utilized in the manufacturing of liquid fertilizers.
• It works as a pH controlling agent industrially.
• It gives pharmaceutical aid being an alkalized compound.
• It is mordant food.
• It is used in manufacturing liquid soap.
• Potassium Hydroxide works as an absorbent for carbon dioxide.
• It is used in making paints.

Preparation 

It is prepared by reacting potassium chloride with water. It is also prepared by treating slaked lime (solution of calcium hydroxide) with potassium carbonate (K₂CO₃).

Chemical Properties

• It decomposes when heated and emits fumes of potassium oxide.
• It reacts with carbon dioxide and water.
• Its vapour pressure is 1mm/Hg.
• Its heat of fusion is 7.5kj/mol.
• It is soluble in glycerine, etc.
• It is considered safe, as the FDA states that it can be used directly.