Potassium Oxide

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Potassium oxide is made up of potassium and oxygen, joined together by ionic bonds. Potassium has an oxidation state of +1. So it can easily lose one electron. Potassium belongs to the group of alkali metals. It has a high tendency of combining with any other counter ion to complete its valency. So, it is highly reactive in free form. It readily reacts with oxygen to form Potassium Hydroxide. It has a pale yellow appearance and is widely used as a fertilizer. It is a strongly corrosive alkali when dissolved in water.  Here, we will study about Potassium oxide formula, structure, physical and chemical properties, and uses. Potassium oxide is a strongly corrosive alkali when dissolved in water.


The potassium Oxide formula contains two atoms of potassium and one atom of Oxygen. These atoms are joined by bonds. Potassium is in a +1 oxidation state. Oxygen has an oxidation state of -2. To balance the valency, Two atoms Of potassium combine with One atom of oxygen. So, the formula of potassium oxide is K2O

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Physical Properties 

  • It is solid and pale yellow in color.

  • The molecular weight is 94.2 g/mol.

  • The density of K2O is  2.35 gm/cm3.

  • The melting Point of potassium oxide is 740℃.

  • It is soluble in ether and ethanol.

Chemical Properties

  • Potassium burns in the atmosphere (O2 )to make potassium oxide.

​4K + O2 → 2K2O

  • When Potassium hydroxide is treated with water, it forms the hydroxide of potassium.

K2O + H2O → KOH

  • When it is reacted with a strong acid, it results in the formation of salt and water.

K2O + HCl → KCl + H2O

  • Potassium can be added directly to water

2K + 2H2O → 2KOH + H2

Applications and Uses

  • It is used as a fertilizer in the agriculture industry.

  • It is not soluble in water and highly stable. This makes it useful in the ceramic industry. It is used in making lightweight bowls and structural compounds in aerospace.

  • It is used for preparing soaps and glass. It is commonly known as pure potash.

  • It is used to cure fungal infections such as zygomycetes

  • It is also used in the treatment of animal-related diseases.


In this article, we learned about potassium oxide, the formula of potassium oxide, its chemical and physical properties, and its applications of it. It is an ion compound. It forms salt and water on being treated with an acid. It is also used as a fertilizer in the agricultural industry. It may be toxic when inhaled and ingested. It is useful in ceramic, glass, and optic industries.

Did You Know?

It must be noted that potassium oxide has the chemical formula K2O. While potassium Superoxide is an inorganic compound with the chemical formula KO2. It is a yellow-colored paramagnetic solid which decomposes in moist air. The oxidation state of oxygen in potassium superoxide is calculated as -1. These two compounds are totally different from each other in terms of chemical and physical properties.

FAQ (Frequently Asked Questions)

Question: What happens when Potassium is Exposed to Air?

Answer: Three compounds are formed during the reaction, they are potassium oxide, potassium peroxide, and potassium superoxide. Potassium is a very active metal that reacts violently with oxygen in the presence of air. Potassium oxidizes faster than most of the metals and forms oxides with oxygen-oxygen bonds. 

8K + 4O2  → 2K2O+ 2KO2 + K2O2

Question: Is Potassium Hydroxide Dangerous?

Answer: Potassium hydroxide is an inorganic compound with the chemical formula KOH. It should always be kept in mind that all chemical products are to be handled with care and safety measures. It can cause skin irritation on contact with skin. It may lead to severe eye damage if it gets into the eyes. On the inhalation, it causes shortness of breath and cough. So, we should always wear lab coats, gloves, and safety glasses while working in the laboratory.

Question: What is Potassium Hydroxide used for? 

Answer: It is used as a fertilizer in the agriculture industry. It is insoluble in water. Which makes it useful in ceramic, glass, and optic industries.  It is used in the manufacture of medicines for animal diseases and human-related fungal infections. It is used in the manufacturing of soaps.