Potassium Hydroxide - Formula, Uses, Properties, Structure, FAQs

Potassium Hydroxide

Potassium hydroxide, also known as caustic potash, is an inorganic substance and potassium hydroxide formula or caustic potash formula is KOH. Caustic potash, lye, and potash lye are all names for potassium hydroxide. This base is made up of alkali metal hydroxide, which is a very potent alkali metal. It has the appearance of a transparent solution in its aqueous state. KOH comes in a variety of solid forms, including white to slightly yellow lumps, flakes, pellets, and rods. In its solid state, this chemical does not have a distinctive odour. KOH chemical name is potassium hydroxide.

• Caustic potash is another name for potassium hydroxide.

• It is an inorganic substance.

• The chemical formula of potassium hydroxide is KOH.

• KOH has a molecular weight/molar mass of 56.11 g/mol.

• It is non-flammable but quite corrosive.

• Chemical manufacture, cleaning compounds, and petroleum refining all use it.

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It also has a caustic tendency, which means it causes a burning feeling and is irritating to the skin when exposed to it. It is recommended that it be used and handled with care. It is also a very caustic substance. It has the ability to corrode metals as well as living cells and tissues. Potassium hydroxide is an alkali metal hydroxide. As a result, it is a strong base. It is, in fact, one of the most stable bases. At standard conditions, the pH of a 1 mol/L KOH solution is 10.98, which is quite high.

Pellets of Potassium Hydroxide

Properties of Potassium Hydroxide

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Structure of Potassium Hydroxide

(3 D structure of KOH)

The chemical formula for potassium hydroxide is KOH. Hydroxide (OH^–) is made up of one hydrogen and one oxygen atom with a charge of -1. The alkali metal potassium (K⁺) has a charge of +1. As a result, the equation is balanced, and the charges are distributed evenly. The chemical formula of caustic potash is KOH. The distance between K⁺ and OH^- ions lies between 2.69 and 3.15 A◦.

Although KOH can exist as a crystalline solid comparable to sodium chloride, it usually forms crystalline hydrates due to its great affinity for water. The most frequent hydrates of caustic potash are mono, di, and tetra, which have one, two, or four water molecules bonded to one molecule of potassium hydroxide, respectively.

Solubility of Potassium Hydroxide

Potassium hydroxide is highly soluble in water, ethanol, methanol, and glycerin.

• Potassium hydroxide is mildly soluble in ether.

Preparation of Potassium Hydroxide

Electrolysis of KCl

Electrolysis of potassium chloride solution produces potassium hydroxide on an industrial scale. The process is also known as the chloralkali process.

2KCl + 2H₂O → KOH + Cl₂ + H₂

2. Salt metathesis Reaction

Though KOH is now made by electrolysis with KCl, it was previously made by a salt metathesis reaction of calcium hydroxide and potassium carbonate. The two reactant compounds react to generate two new compounds as products in a salt metathesis process, where their respective components or constituents change places.

Ca (OH) ₂ + K₂CO₃ → CaCO₃ + KOH

Potassium Hydroxide Uses:

• When compared to NaOH, potassium hydroxide solution is more conductive, hence it is utilised as an electrolyte in some alkaline batteries.

• In the food sector, it is utilised as a pH control agent.

• It is a thickening agent for food.

• It is employed in semiconductor chip production.

• It is used to make cuticle removers, which are used for manicure treatments.

• It aids in the identification of fungus species.

• Cotton is mercerized with it.

• In analytical chemistry, it is employed in alkalimetric titrations.

• It is used in the production of liquid fertilisers.

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Chemical Properties of Potassium Hydroxide

1. Saponification of ester

The ester is saponified in a sealed tube by heating it with a specified amount of potassium hydroxide in an organic solvent. This reaction must be quantifiable and take an acceptable amount of time to be useful analytically. The use of a strong base is one circumstance that promotes a quick and quantitative reaction.

KOH + RCOOR¹ → RCOOK + R¹OH

2. Reaction with Carbon Dioxide

When potassium hydroxide comes into contact with CO_2, it produces bicarbonate.

Because the hydroxide ion combines with carbon dioxide to generate bicarbonate alkalinity, adding hydroxide ions such as lime, sodium hydroxide, or potassium hydroxide modifies the pH.

KOH + CO₂ → KHCO₃

3. Reaction with zinc

With the chemical formula KOH, potassium hydroxide is a strong inorganic alkaline substance. It is very corrosive to metal and tissue since it is a noncombustible, hydrophilic material. It easily absorbs moisture from the air and produces a caustic solution that corrodes aluminium and zinc.

KOH + Zn → K₂ZnO₂ + H₂

Health Hazards of Potassium Hydroxide

Potassium hydroxide's health risks are similar to those of other powerful alkalis, such as sodium hydroxide. Skin, mucous membranes, and eyes can be severely irritated by potash lye and its solution. It can generate heat and cause combustion when it comes into touch with water or moisture. Tissues are corroded by potassium hydroxide.

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