Potassium Hydroxide is an odorless, white or slightly yellow,flakey or lumpy solid which is often in a water solution. lt isused in making soap, as an electrolyte in alkaline batteries andin electroplating, lithography, and paint and varnish removers.Liquid drain cleaners contain 25 to 36% of Potassium Hydroxide.

Lewis structure

Reactions

Potassium hydroxide solution in water is a strong base. It reacts violently with acid and is corrosive to metals such as aluminium, tin, lead and zinc. This produces a combustible/explosive gas. Reacts with ammonium salts. This produces ammonia. This generates fire hazard.

Preparation

Potassium Hydroxide was made by adding potassium carbonate to a strong solution of calcium hydroxide (slaked lime). The salt metathesis reaction results in precipitation of solid calcium carbonate, leaving potassium hydroxide in solution:

Ca(OH)2 + K2CO3 → CaCO3 + 2 KOH

Filtering off the precipitated calcium carbonate and boiling down the solution gives potassium hydroxide ("calcinated or caustic potash"). This method of producing potassium hydroxide remained dominant until the late 19th century, when it was largely replaced by the current method of electrolysis of potassium chloride solutions.[11] The method is analogous to the manufacture of sodium hydroxide (see chloralkali process):

2 KCl + 2 H2O → 2 KOH + Cl2 + H2

Hydrogen gas forms as a byproduct on the cathode; concurrently, an anodic oxidation of the chloride ion takes place, forming chlorine gas as a byproduct. Separation of the anodic and cathodic spaces in the electrolysis cell is essential for this process.

Uses

Potassium hydroxide is used in water treatment for pH adjustment (AWWA, 2017);

Use as a Precursor to Other Water Treatment Chemicals;

Potassium hydroxide is used to manufacture potassium permanganate.

Other Applications

Potassium hydroxide is the most common intermediate used to manufacture potassium-based inorganic chemicals. The most common chemical produced from potassium hydroxide is potassium carbonate, which has a wide variety of uses in agriculture and manufacturing. Other significant applications of potassium hydroxide are manufacturing fertilizers and soil amendments, soaps and detergents, food processing, battery production, deicing, and petroleum refining (NCBI, 2021; USDA, 2016).

Hazards

Potassium Hydroxide can affect you when inhaled and bypassing through the skin.

Potassium Hydroxide is a HIGHLY CORROSIVE

CHEMICAL and contact can severely irritate and burn theskin and eyes leading to eye damage.

Contact can irritate the nose and throat.

lnhaling Potassium Hydroxide can irritate the lungs.

Higher exposures may cause a build-up of fluid in the lungs(pulmonary edema), a medical emergency.

Exposure to Potassium Hydroxide can cause headache,dizziness,nausea and vomiting.

Potassium Hydroxide may cause a skin allergy.