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Chemistry > Chemical Reactions and Equations > Potassium Hydroxide – Definition, Formulas, Uses
Chemical Reactions and Equations

Potassium Hydroxide – Definition, Formulas, Uses

Introduction to Potassium Hydroxide

Potassium hydroxide is a very important inorganic base and is also referred to as caustic potash or we also call it as potash lye. It is solid in white colour that is very dangerously corrosive. Many of the commercial samples are 90% pure, the remainder being the carbonates and the water.

It produces around 100 times more NaOH than the KOH in a year. KOH is noteworthy as a precursor to many of the soft soaps in the form of liquid.

potassium hydroxide

Definition of Potassium Hydroxide

Potassium hydroxide is basically an inorganic compound that has a formula ‘KOH’. Along with the sodium hydroxide that is NaOH, this solid is a prototypical strong base and is also colourless. Moreover, it has multiple industrial and niche applications, most of these exploits their caustic nature and their reactivity for the acids.

Properties of Potassium Hydroxide

Potassium hydroxide is available as the translucent pellets. These become tacky in the air because the KOH is hygroscopic. Consequently, KOH typically consists of varying amounts of water i.e. H2O.

Furthermore, its dissolution in the water (H2O) is extremely exothermic. Along with this, the concentrated aqueous solutions are many times referred to as potassium lye.

Even at the excess temperatures. The solid KOH doesn’t readily dehydrate.

Structure of Potassium Hydroxide

At hot temperatures, the solid KOH crystallizes in the form of NaCl crystalline structure. The OH group is either randomly or rapidly disordered. This occurs so that the OH- group is effectively a round shape anion that has a radius of 1.53 A and it is between Cl and F in size.

However, at room temperature, it orders the OH- group and the environment about K+ centres are distorted. With the K+_OH- distances having a range of 2.69 to 3.15 A, it depends on the orientation of the OH group.

KOH produces a series of crystalline hydrates. Namely the monohydrate KOH. H2O, the dehydrate KOH. 2H2O and tetra-hydrate KOH. 4H2O.

The Formula of Potassium Hydroxide

The chemical formula for the element potassium hydroxide is KOH. Moreover, the Molar Mass of the Potassium Hydroxide is 56.11 g/mol. The structure of KOH contains an ionic bond that is between the potassium metal cation and the hydroxyl anion.

Furthermore, The solid KOH is present in a rhombohedral crystalline structure. This structure is much similar to that of sodium chloride. K8

Preparation and Purification Potassium Hydroxide

Firstly, the industrial preparation of the KOH is way similar to that of the NaOH. This happens because of the chloralkali process.

Its preparation consists of the electrolysis of the potassium chloride solutions. This happens with chlorine gas as a by-product:

2 KCl + 2 H2O → 2 KOH + Cl2 + H2

Uses of Potassium Hydroxide

Preparation of salts: it is strongly alkaline. The potassium hydroxide reacts with the multiple acids.

Furthermore, this acid-base reaction comes in use for producing the potassium salts. These salts, in turn, have a number of various applications.

Neutralization of Acids: as an alkali, we use potassium hydroxide for neutralizing acidity and adjusting the pH of Solutions. Furthermore, in the chemical analysis, it is an important and valuable agent for the titration of the acids for determining their concentration.

Production of Soaps: the reaction process of the potassium hydroxide with the oils and fats under the heating conditions is a process we call saponification. In addition, this reaction is useful for producing potassium soaps.

These are softer and more soluble than the soaps derived with sodium hydroxide. And many other uses are there.

Solved Question for You

Ques. Lye is useful for soap-making. Lye is a concentrated solution for which of the following compound?

(A). K2CO3.
(B). CuSO4.
(C). NaOH.
(D). NaCl.

Ans. (A). K2CO3.

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