What is the Difference Between Potassium Carbonate and Potassium Bicarbonate

Potassium carbonate and potassium bicarbonate are two compounds containing potassium, each with distinct properties and applications. Understanding the difference between potassium carbonate and potassium bicarbonate is essential for their proper utilization in different fields.

What is the difference between potassium carbonate and potassium bicarbonate? Potassium carbonate contains potassium, carbon, and oxygen, whereas potassium bicarbonate contains potassium, carbon, oxygen, and hydrogen.

Key Areas Covered

1. What is Potassium Carbonate  
      – Definition, Features
2. What is Potassium Bicarbonate
      – Definition, Features
3. Similarities Between Potassium Carbonate and Potassium Bicarbonate
      – Outline of Common Features
4. Difference Between Potassium Carbonate and Potassium Bicarbonate
      – Comparison of Key Differences
5. FAQ: Potassium Carbonate and Potassium Bicarbonate
      – Answers to Frequently Asked Questions

Key Terms

K2CO3, Potash, Pearl Ash, Potassium Carbonate, Potassium Bicarbonate

Potassium Carbonate and Potassium Bicarbonate

What is Potassium Carbonate

Potassium carbonate, with the chemical formula K2CO3 is a compound with various applications in chemistry, industry, and agriculture. This white, crystalline substance is often referred to as potash or pearl ash. Its chemical structure consists of two potassium ions, one carbon atom, and three oxygen atoms.

In aqueous solutions, potassium carbonate readily dissociates into potassium ions and carbonate ions. This property makes it a useful electrolyte in certain chemical processes and contributes to its alkaline nature. The alkalinity of potassium carbonate is exploited in various industrial applications, such as in the production of glass and soap. In glass manufacturing, it helps lower the melting point of silica, facilitating the formation of glass at lower temperatures. In soap production, it functions as a pH regulator and contributes to the soap’s cleaning properties.

Potassium Carbonate

Furthermore, potassium carbonate plays a crucial role in various chemical reactions, serving as a base and participating in acid-base titrations. Its ability to absorb moisture from the air makes it effective as a desiccant, aiding in drying processes.

In agriculture, potassium carbonate is used as a source of potassium, an essential nutrient for plant growth. Its application helps enhance soil fertility and crop yield.

What is Potassium Bicarbonate

Potassium bicarbonate (KHCO3) is a chemical compound with many applications in various industries and everyday life. It is the potassium salt of carbonic acid and is known for its white, crystalline appearance. This compound is a mild alkaline substance, often used as a buffering agent and leavening agent in the food industry, particularly in baking.

In chemistry, potassium bicarbonate plays a role in maintaining pH balance. As a weak base, it can react with acids to form carbon dioxide, water, and a corresponding salt. This property is exploited in the culinary world, where it serves as a leavening agent in baking powder. When combined with an acid, such as cream of tartar, it produces carbon dioxide gas, causing dough or batter to rise, resulting in a lighter texture in baked goods.

Potassium Bicarbonate

Beyond its culinary applications, potassium bicarbonate is employed in fire extinguishers as an effective means of suppressing fires involving oils and fats. The compound releases carbon dioxide upon decomposition, displacing oxygen and smothering the flames. Additionally, its use in agriculture as a foliar spray aids in mitigating fungal diseases in plants.

Despite its widespread utility, it’s essential to handle potassium bicarbonate with care, as it can irritate the respiratory system and eyes.

Similarities Between Potassium Carbonate and Potassium Bicarbonate

  1. Potassium carbonate and potassium bicarbonate are potassium salts with similar chemical properties.
  2. Both compounds are soluble in water and can act as alkaline substances when dissolved, contributing to the pH of a solution.

Difference Between Potassium Carbonate and Potassium Bicarbonate


Potassium carbonate is a white, odorless solid compound with the chemical formula K2CO3, while potassium bicarbonate is a white, crystalline compound with the chemical formula KHCO3.


While potassium carbonate consists of two potassium ions and one carbonate ion, potassium bicarbonate consists of one potassium ion and one bicarbonate ion.


Potassium carbonate is a stronger base than potassium bicarbonate.


Potassium bicarbonate is soluble but less so than potassium carbonate.


Moreover, potassium carbonate is commonly used in industries such as glass manufacturing and soap production, whereas potassium bicarbonate is used as a leavening agent in baking and as a source of potassium supplementation.


In conclusion, the difference between potassium carbonate and potassium bicarbonate lies in their chemical composition. Potassium carbonate, a strong alkaline compound, is useful in various sectors, from glass and soap production to agriculture, enhancing soil fertility. On the other hand, potassium bicarbonate, milder in alkalinity, serves roles in the food industry, acting as a buffering and leavening agent in baking while also proving effective in fire extinguishers and agriculture. Despite their differences, both salts share solubility in water and alkaline characteristics. Understanding these differences allows for informed applications, emphasizing the importance of proper handling, particularly with potassium bicarbonate due to its potential respiratory and ocular irritations.

FAQ: Potassium Carbonate and Potassium Bicarbonate

1. What is the common name for potassium carbonate?

Potassium carbonate is also called carbonate of potash or pearl ash. It is named “carbonate of potash” because it is composed of carbonate ions and potassium and is historically derived from potash sources. The term “pearl ash” likely originated from its appearance when processed into small, pearl-like granules.

2. What’s the difference between potassium hydroxide and potassium bicarbonate in terms of the chemical formulae?

Potassium hydroxide is represented by the formula KOH, indicating one potassium atom (K) bonded to one hydroxide ion (OH⁻). In contrast, potassium bicarbonate has the formula KHCO₃, signifying one potassium atom (K) bonded to one bicarbonate ion (HCO₃⁻), which consists of one hydrogen atom (H), one carbon atom (C), and three oxygen atoms (O).

3. Why is potassium bicarbonate used?

Potassium bicarbonate is used as an antacid, electrolyte replenisher, and potassium supplement. It can also be used as an excipient in drug formulations.

4. What is the difference between potassium carbonate and sodium bicarbonate?

Potassium bicarbonate replaces the sodium with potassium and has the chemical formula KHCO3. This substitution results in different chemical formulas and slightly different properties.

5. What is a potassium bicarbonate substitute?

A common substitute for potassium bicarbonate is sodium bicarbonate, also known as baking soda. While they have slightly different chemical compositions, both compounds can serve similar purposes in certain applications, such as in baking, where they act as leavening agents to help the dough rise.  


1. “Potassium Carbonate.” PubChem. National Library of Medicine. 
2. “Potassium Bicarbonate.” Wikipedia. Wikipedia Foundation.

Image Courtesy:

1. “Potassium Carbonate” By Walkerma assumed – No machine-readable source provided. Own work assumed (based on copyright claims) (Public Domain) via Commons Wikimedia
2. “Potassium bicarbonate” By User: Edgar181 – Own work (Public Domain) via Commons Wikimedia

About the Author: Hasini A

Hasini is a graduate of Applied Science with a strong background in forestry, environmental science, chemistry, and management science. She is an amateur photographer with a keen interest in exploring the wonders of nature and science.

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