Potassium carbonate

Carbonate of potash redirects here. For one of potassium carbonate's impure forms, see potash.

Potassium carbonate is a white salt, soap and glass.

History

Potassium carbonate was first identified in 1742 by Antonio Campanella and is the primary component of potash in a kiln to remove impurities. The fine white powder remaining was the pearlash. The first patent issued by the U.S. Patent Office was awarded to Samuel Hopkins in 1790 for an improved method of making pearlash.

In late 18th century North America, before the development of baking powder, pearlash began to be used as a leavening agent in "quick breads".

Other terms for potassium carbonate:

• Carbonate of potash
• Dipotassium carbonate
• Dipotassium salt
• Pearl ash
• Potash
• Salt of tartar
• Salt of wormwood

Production

Today potassium carbonate is prepared commercially by the potassium compounds.

2KOH + CO₂ → K₂CO₃ + H₂O

Applications

Pearlash has been used for soap, glass, and china production.

In the laboratory, it may be used as a mild calcium chloride may be incompatible. However, it is not suitable for acidic compounds.

Mixed with water it causes an exothermic reaction that results in a temperature change, producing heat.

In cuisine, it is used as an ingredient in the production of grass jelly, a food consumed in Chinese and Southeast Asian cuisines.

Potassium carbonate is being used as the electrolyte in many cold fusion experiments.

References

A Dictionary of Science, Oxford University Press Inc., New York 2003