Potassium Bicarbonate

OVERVIEW

Potassium bicarbonate (poe-TAS-ee-yum buy-KAR-bo-nate) is a colorless crystalline solid or white powder with no odor and a salty taste. It occurs naturally in salt beds, sea water, silicate rocks, and a number of foods, primarily fruits and vegetables. Potassium bicarbonate is also present in the tissues of humans and other animals, where it is involved in a number of essential biological processes, including digestion, muscle contraction, and heartbeat. It is used primarily in cooking and baking, as a food additive, and in fire extinguishers.

HOW IT IS MADE

Potassium bicarbonate is made by passing carbon dioxide gas through an aqueous solution of potassium carbonate: K₂CO₃ + CO₂ + H₂O → 2KHCO₃

KEY FACTS

OTHER NAMES:

Potassium acid carbonate; potassium hydrogen carbonate

FORMULA:

KHCO₃

ELEMENTS:

Potassium, hydrogen, carbon, oxygen

COMPOUND TYPE:

Acid salt (inorganic)

STATE:

Solid

MOLECULAR WEIGHT:

100.12 g/mol

MELTING POINT:

decomposes above 100°C (212°F)

BOILING POINT:

Not applicable

SOLUBILITY:

Soluble in water; insoluble in ethyl alcohol

COMMON USES AND POTENTIAL HAZARDS

One of the most familiar applications of potassium bicarbonate is as an antacid to treat the symptoms of upset stomach. The compound reacts with stomach acid—hydrochloric acid; HCl—to relieve gaseous distress, stomach pain, and heartburn. The compound can also be used to treat potassium deficiency in the body. Some research suggests that potassium bicarbonate may help restore muscle and bone tissue, particularly in women with the degenerative bone disease osteoporosis. The compound is also used as a food additive, as a leavening agent, to maintain proper acidity in foods, to supply potassium to a diet, and to provide the bubble and fizz in carbonated drinks.

Potassium bicarbonate is also used in certain types of fire extinguishers. When such an extinguisher is used, the potassium bicarbonate reacts with an acid present in the device to produce carbon dioxide. The carbon dioxide propels a liquid from the extinguisher and, itself, helps put out a fire. Potassium bicarbonate is also used in agriculture to maintain proper acidity in soils and to supply potassium that may be missing from the ground.

Under normal circumstances, potassium bicarbonate poses no health threat to humans. Excess potassium in the body may result in a condition known as hyperkalemia, characterized by tingling of the hands and feet, muscle weakness, and temporary paralysis. Such a condition is very rare when potassium bicarbonate is used in normal amounts.

Interesting Facts

Potassium bicarbonate can be substituted for baking soda (sodium bicarbonate; NaHCO₃) for people who are on a low-sodium diet.

FOR FURTHER INFORMATION

"Potassium Bicarbonate." Yale New Haven Health Drug Guide. http://yalenewhavenhealth.org/library/healthguide/en-us/drugguide/topic.asp?hwid=d03600a1 (accessed on October 31, 2005).

"Potassium Bicarbonate Handbook." Armand Products Company. Available online at http://www.oxy.com/OXYCHEM/Products/potassium_bicarbonates/literature/Po0tBiVs6.pdf (accessed on October 31, 2005).

Rowley, Brian. "Fizzle or Sizzle? Potassium Bicarbonate Could Help Spare Muscle and Bone." Muscle & Fitness (December 2002): 72.

"Strong Muscle and Bones." Prevention (June 1, 1995): 70-73.

See AlsoSodium Bicarbonate