View source for Ammonium bicarbonate

[[File:Ammonium_bicarbonate.jpg|thumb|300px|Food grade (NH<sub>4</sub>)HCO<sub>3</sub>]]
'''Ammonium bicarbonate''' or '''ammonium hydrogen carbonate''' is an inorganic compound with the chemical formula (NH<sub>4</sub>)HCO<sub>3</sub>. In older literature it may be referred to as '''hartshorn''', as is [[ammonium carbonate]].

==Properties==
===Chemical===
Ammonium carbonate will slowly decompose to give off ammonia, carbon dioxide and water vapors. The reaction occurs faster at higher temperatures:

:(NH<sub>4</sub>)HCO<sub>3</sub> → NH<sub>3</sub> + H<sub>2</sub>O + CO<sub>2</sub>
[[Ammonium carbamate]] is another potential by-product of decomposition.

When treated with acids, it releases carbon dioxide:

:(NH<sub>4</sub>)HCO<sub>3</sub> + HCl → NH<sub>4</sub>Cl + H<sub>2</sub>O + CO<sub>2</sub>

It also reacts with alkali metal halides, giving ammonium halide and alkali metal bicarbonate:
:NH<sub>4</sub>HCO<sub>3</sub> + LiCl → NH<sub>4</sub>Cl + LiHCO<sub>3</sub>
:NH<sub>4</sub>HCO<sub>3</sub> + NaBr → NH<sub>4</sub>Br + NaHCO<sub>3</sub>
:NH<sub>4</sub>HCO<sub>3</sub> + KI → NH<sub>4</sub>I + KHCO<sub>3</sub>

===Physical===
Ammonium bicarbonate is a white salt, soluble in water, but insoluble in methanol. It will slowly decompose over time, to give off [[ammonia]] gas, giving the salt a strong smell. The decomposition occurs faster at high temperatures.

==Availability==
Ammonium bicarbonate can be bought from food stores as "smelly" baking powder, either pure or mixed with other carbonates, such as [[sodium bicarbonate]] or [[magnesium carbonate]]. Sometimes it's referred to as simply "ammonium", usually the label name.

==Preparation==
Ammonium bicarbonate can be made by bubbling [[carbon dioxide]] gas through a cold solution of ammonia, at acidic pH.

:CO<sub>2</sub> + NH<sub>3</sub> + H<sub>2</sub>O → (NH<sub>4</sub>)HCO<sub>3</sub>
Alternatively, it can be made by heating a mixture of [[ammonium nitrate]], sodium bicarbonate or carbonate, and water in one container, and channeling the generated gases into a chilled empty container, where it will crystallize on the walls.

==Projects==
*[[Ammonium carbonate]] synthesis
*Generate ammonia gas

==Handling==
===Safety===
Ammonium bicarbonate gives off ammonia fumes, which are irritating and toxic if they build up in a closed environment.

===Storage===
Ammonium bicarbonate is best stored in closed containers and kept in cold places.

===Disposal===
Ammonium bicarbonate can be neutralized and safely discarded, as it poses no danger to the environment.

==References==
<references/>
===Relevant Sciencemadness threads===
[[Category:Chemical compounds]]
[[Category:Inorganic compounds]]
[[Category:Bicarbonates]]
[[Category:Materials unstable in acidic solution]]
[[Category:Readily available chemicals]]
[[Category:Ammonium compounds]]