Ammonium Bicarbonate

What is Ammonium Bicarbonate?

Ammonium bicarbonate is an inorganic compound that is mildly basic. It consists of the ammonium cation and the bicarbonate anion. The molecular or chemical formula of Ammonium bicarbonate is NH4HCO3. It appears as a crystalline solid white and has a strong smell of ammonia. It readily dissolves in water but insoluble in most various organic solvents. When Ammonium bicarbonate is dissolved in water, it gives you a mildly alkaline solution.

Ammonium Bicarbonate Structure

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Properties of Ammonium Bicarbonate

General Properties

Molar Mass/Molecular Weight

79.055 g/mol

Physical Properties

Colour and Appearance

White or colourless


Faint ammoniacal

Melting Point

41.9 °C, 107.4 °F (decomposes)


1.586 g cm-3



State of matter at room temperature

Crystalline solid


Soluble in water, insoluble in acetone, benzene, methanol, and ethanol

Solubility in Water

17.4 g/100 cc at 20 °C

Salt of Hartshorn

The compositions contain ((NH4)2CO3) which is the chemical name of ammonium carbonate. They were produced commercially and formerly referred to as spirits of ammonia or salt of hartshorn. It is obtained by the dry distillation of nitrogenous organic matter like hair, horn, leather. In addition to ammonium bicarbonate, this material contains carbamate (NH4CO2NH2), and carbonate ((NH4)2CO3). Ammonium Carbonate may be a non-toxic white crystalline salt with the formula (NH4)2CO3. It is also known as hartshorn or baker’s ammonia.

Since it readily degrades to gaseous ammonia and carbon dioxide upon heating, it is used as a leavening agent and also as a smelling salt. It was a predecessor to the more modern leavening agents baking soda and baking powder. It is also used in some smokeless tobacco products and as an active ingredient in cough syrup to relieve the symptoms of bronchitis. Its use as a leavening agent goes back centuries. It is the predecessor to the more modern leavening agents baking soda and baking powder. A similar decomposition takes place when the carbonate is exposed to air.

Ammonium Bicarbonate Production

Ammonium bicarbonate is produced by combining CO2 and ammonia:

CO2 + NH3 + H2O → (NH4) HCO3

The reaction solution is kept cold because ammonium bicarbonate is thermally unstable. It allows the precipitation of the merchandise as white solid. About 100,000 tons were produced during this way in 1997. 

The compound on exposure to air gives off ammonia and returns to ammonium bicarbonate form. Ammonia gas converts (NH4)2CO3, and H2O) into normal carbonate ((NH4)2CO3) when it passes into a robust solution of the carbonate (a 2:1:1 mixture of (NH4)HCO3. It may obtain in the crystalline condition from an answer prepared at about 30 °C. 

Ammonium Bicarbonate Uses

Ammonium bicarbonate is employed within the food industry as a leavening agent for flat food, like cookies and crackers. It was commonly utilized in the house before modern-day leaven was made available. In many cases, it replaces bicarbonate of soda or a mixture of both, counting on the recipe composition and leavening requirements. Compared to baking soda, hartshorn has the advantage of producing more gas for the same amount of agent, and of not leaving any salty or soapy taste in the finished product, because it completely decomposes into water and gaseous products that evaporate during baking. It cannot be used for moist, bulky food, like regular bread or cakes since some ammonia is going to be trapped inside and can cause an unpleasant taste. 

Ammonium bicarbonate is used as an inexpensive nitrogen fertilizer in China but is now being phased out in favour of urea for quality and stability. This compound is employed as a component of fire-extinguishing compounds, pharmaceuticals, dyes, pigments, and it is also an essential fertilizer, being a source of ammonia within the production. It widely remains utilized in the plastics and rubber industry, in the manufacture of ceramics, in chrome leather tanning, and for the synthesis of catalysts.

It is also used for buffering solutions to form them slightly alkaline during chemical purification, like high-performance liquid chromatography. Because it entirely decomposes to volatile compounds, this enables rapid recovery of the mixture of interest by freeze-drying. Ammonium bicarbonate is additionally a vital component of the expectorant cough syrup.

Health Effects/Safety Hazards of Ammonium Bicarbonate

In low concentrations, it is not considered hazardous. Its primary health hazard is its decomposition reaction giving sour ammonia gas, which is a severe irritant. Inhalation of ammonium bicarbonate can irritate the eyes, skin, nose, and full system respiratory, and cause severe coughing and difficulty in breathing.

FAQ (Frequently Asked Questions)

1. Is Ammonium Bicarbonate Toxic?

Ammonium Carbonate is a crystalline, non-toxic, white-coloured salt with the formula (NH4)2CO3. It is also known as baker’s ammonia and also as hartshorn. Ammonium carbonate is water-soluble, and the compound decomposes in hot water.

2. What is an Ammonium Bicarbonate Structure?

The chemical ammonium bicarbonate formula is NH4HCO3. Its molecular formula is CH5NO3, and its molar mass is 79.056 g/mol. Its chemical structure consists of the ammonium cation (NH4+) and the bicarbonate anion (HCO3-).

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3. What is Ammonium Bicarbonate Powder?

It is a leavening agent and the forerunner of today’s baking powder and baking soda. Originally made up of the bottom antlers of reindeer, this is often considered as an ancestor of new backing soda. Northern Europeans make it useful for their springerle and gingerbread cookies, light and crisp. Unfortunately, it can impart an unpleasant ammonia flavour, so it is best utilised for cookies and pastries that are sufficiently small to permit the ammonia odour to dissipate while baking. It can be found in drug stores, baking supply stores, or an order catalogue. Must be ground into a powder before using it. The ordinary household ammonia is different from a poisonous commercial, so do not confuse.  Its substitution is One teaspoon of baker’s ammonia = one teaspoon baking powder or one teaspoon baking powder + one teaspoon baking soda.