Potassium Carbonate - K2CO3

What is Potassium Carbonate?

K2CO3 is an inorganic compound with chemical name Potassium carbonate.

It is also called Carbonate of potash, or Dipotassium carbonate or Pearl ash. It is a dipotassium salt of carbonic acid. It is widely used in the production of glass and soap.

Pearl ash is hygroscopic, deliquescent powder white in colour. It is odourless and tastes like alkaline. It is readily soluble in water but insoluble in ethanol, acetone, and alcohol. It has a pH of 11.6. It is a primary component of potash.

Historically, Dipotassium carbonate was created by baking potash in a kiln. The white powder produced was the potassium carbonate. In the year 1790, Samuel Hopkins was awarded the first patent which was issued by the US Patent Office for an improved method of pearl ash and making potash.

Properties of Potassium Carbonate – K2CO3

K2CO3 Potassium carbonate
Molecular weight/molar mass of K2CO3 138.205 g/mol
Density of Potassium carbonate 2.43 g/cm3
Boiling Point of Potassium carbonate Decomposes
Melting Point of Potassium carbonate 891 °C

Potassium Carbonate Structure – K2CO3

Potassium Carbonate Structure

Potassium Carbonate Structure – K2CO3

K2CO3 Uses (Potassium carbonate)

  • Potassium carbonate is used as a mild drying agent.
  • Used in the making of grass jelly.
  • Used to produce Dutch process chocolate by alkalization.
  • Used in the production of wire or mead by acting as a buffering agent.
  • Used to soften hard water.
  • Used in welding fluxes.
  • Used as a fire suppressant.

Production of Potassium Carbonate

1. It is prepared commercially by reacting potassium hydroxide (KOH) with carbon dioxide (CO2):

2 KOH + CO2 → K2CO3 + H2O

2. An alternative method, to obtain this compound is by treating it with carbon dioxide (CO2) in the presence of an organic amine which results in potassium bicarbonate and on further calcination of KHCO3 gives potassium carbonate.

2 KHCO3 → K2CO3 + H2O + CO2

Health hazards

Pearl ash is non-combustible. When it comes in contact with skin, eyes, and respiratory tract can cause irritation.

Frequently Asked Questions

What are the uses of potassium carbonate?

Potassium carbonate is widely used for the production of glass and soap. It is also used as a drying agent which is mild in nature. Many wine production processes involve the use of this compound as a buffering agent. Potassium carbonate is also used as a fire suppressant.

How can potassium carbonate be prepared?

Potassium carbonate is commercially prepared with the help of a reaction involving carbon dioxide and potassium hydroxide. In an alternative process, in the presence of an organic amine, potassium chloride is treated with carbon dioxide to give potassium bicarbonate which is then calcined to provide potassium carbonate.

Comment on the solubility of potassium carbonate in water

Potassium carbonate is highly soluble in water. However, when dissolved in water, this compound dissociates into potassium and carbonate ions. At a temperature of 20 degrees celsius, the solubility of this compound in water corresponds to 1120 grams per litre.

Learn more about the Structure, physical and chemical properties of K2CO3 from the experts at BYJU’S.

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