Ball-and-stick model of the ammonia molecule
Space-filling model of the ammonia molecule
Stereo structural formula of the ammonia molecule
IUPAC name
Other names
Hydrogen nitride

Trihydrogen nitride

Nitrogen trihydride
3D model (JSmol)
ECHA InfoCard100.028.760
EC Number231-635-3
RTECS numberBO0875000
UN number1005
Molar mass17.031 g/mol
AppearanceColourless gas
Odorstrong pungent odour
Density0.86 kg/m3 (1.013 bar at boiling point)

0.769  kg/m3 (STP)[1]
0.73 kg/m3 (1.013 bar at 15 °C)
681.9 kg/m3 at −33.3 °C (liquid)[2] See also Ammonia (data page)
817 kg/m3 at −80 °C (transparent solid)[3]

Melting point −77.73 °C (−107.91 °F; 195.42 K) (Triple point at 6.060 kPa, 195.4 K)
Boiling point −33.34 °C (−28.01 °F; 239.81 K)
47% w/w (0 °C)
31% w/w (25 °C)
18% w/w (50 °C)[4]
Solubilitysoluble in chloroform, ether, ethanol, methanol
Vapor pressure857.3 kPa
Acidity (pKa)32.5 (−33 °C),[5] 10.5 (DMSO)
Basicity (pKb)4.75
Conjugate acidAmmonium
-18.0·10−6 cm3/mol
Viscosity0.276 cP (−40 °C)
Trigonal pyramid
1.42 D
193 J·mol−1·K−1[6]
−46 kJ·mol−1[6]
Safety data sheetSee: ICSC 0414 (anhydrous)
GHS pictogramsGHS-pictogram-acid.svgGHS-pictogram-skull.svgGHS-pictogram-pollu.svg[7]
H221, H280, H314, H331, H400[7]
P210, P261, P273, P280, P305+351+338, P310[7]
NFPA 704
Flash pointflammable gas
651 °C (1,204 °F; 924 K)
Explosive limits15–28%
Lethal dose or concentration (LD, LC):
0.015 mL/kg (human, oral)
40,300 ppm (rat, 10 min)
28595 ppm (rat, 20 min)
20300 ppm (rat, 40 min)
11590 ppm (rat, 1 hr)
7338 ppm (rat, 1 hr)
4837 ppm (mouse, 1 hr)
9859 ppm (rabbit, 1 hr)
9859 ppm (cat, 1 hr)
2000 ppm (rat, 4 hr)
4230 ppm (mouse, 1 hr)[8]
5000 ppm (mammal, 5 min)
5000 ppm (human, 5 min)[8]
US health exposure limits (NIOSH):[9]
PEL (Permissible)
50 ppm (25 ppm ACGIH- TLV; 35 ppm STEL)
REL (Recommended)
TWA 25 ppm (18 mg/m3) ST 35 ppm (27 mg/m3)
IDLH (Immediate danger)
300 ppm
Related compounds
Other cations
Related nitrogen hydrides
Hydrazoic acid
Related compounds
Ammonium hydroxide
Supplementary data page
Refractive index (n),
Dielectric constantr), etc.
Phase behaviour
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
YesY verify (what is YesYNo ?)
Infobox references

Ammonia is a compound of nitrogen and hydrogen with the formula NH3. The simplest pnictogen hydride, ammonia, is a colourless gas with a characteristic pungent smell. It is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to food and fertilizers. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products. It is mainly collected by downward displacement of both air and water. Ammonia is named for the Ammonians, worshipers of the Egyptian god Amun, who used ammonium chloride in their rituals.[10]

Although common in nature and in wide use, ammonia is both caustic and hazardous in its concentrated form. It is classified as an extremely hazardous substance in the United States, and is subject to strict reporting requirements by facilities which produce, store, or use it in significant quantities.[11]

The global industrial production of ammonia in 2014 was 176 million tonnes,[12] a 16% increase over the 2006 global industrial production of 152 million tonnes.[13] Industrial ammonia is sold either as ammonia liquor (usually 28% ammonia in water) or as pressurized or refrigerated anhydrous liquid ammonia transported in tank cars or cylinders.[14]

NH3 boils at −33.34 °C (−28.012 °F) at a pressure of one atmosphere, so the liquid must be stored under pressure or at low temperature. Household ammonia or ammonium hydroxide is a solution of NH3 in water. The concentration of such solutions is measured in units of the Baumé scale (density), with 26 degrees baumé (about 30% (by weight) ammonia at 15.5 °C or 59.9 °F) being the typical high-concentration commercial product.[15]

Natural occurrence

Ammonia is a chemical found in trace quantities in nature, being produced from nitrogenous animal and vegetable matter. Ammonia and ammonium salts are also found in small quantities in rainwater, whereas ammonium chloride (sal ammoniac), and ammonium sulfate are found in volcanic districts; crystals of ammonium bicarbonate have been found in Patagonian guano.[16] The kidneys secrete ammonia to neutralize excess acid.[17] Ammonium salts are found distributed through fertile soil and in seawater.

Ammonia is also found throughout the Solar System on Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto, among other places: on smaller, icy planets such as Pluto, ammonia can act as a geologically important antifreeze, as a mixture of water and ammonia can have a melting point as low as 173 K (−100 °C; −148 °F) if the ammonia concentration is high enough and thus allow such planets to retain internal oceans and active geology at a far lower temperature than would be possible with water alone.[18][19] Substances containing ammonia, or those that are similar to it, are called ammoniacal.

Other Languages
Afrikaans: Ammoniak
العربية: أمونياك
অসমীয়া: এম’নিয়া
asturianu: Amoniacu
azərbaycanca: Ammonyak
تۆرکجه: آمونیاک
Bân-lâm-gú: A-mó͘-ní-á
беларуская: Аміяк
беларуская (тарашкевіца)‎: Аміяк
български: Амоняк
bosanski: Amonijak
català: Amoníac
Чӑвашла: Аммиак
čeština: Amoniak
chiShona: Ammonia
Cymraeg: Amonia
dansk: Ammoniak
Deutsch: Ammoniak
eesti: Ammoniaak
Ελληνικά: Αμμωνία
español: Amoníaco
Esperanto: Amoniako
estremeñu: Almoniacu
euskara: Amoniako
فارسی: آمونیاک
français: Ammoniac
Gaeilge: Amóinia
Gàidhlig: Amòinia
galego: Amoníaco
ગુજરાતી: નવસાર
गोंयची कोंकणी / Gõychi Konknni: Ammonia
客家語/Hak-kâ-ngî: Â-mô-nì-â
한국어: 암모니아
Հայերեն: Ամոնիակ
हिन्दी: अमोनिया
hrvatski: Amonijak
Ido: Amono
Bahasa Indonesia: Amonia
íslenska: Ammóníak
italiano: Ammoniaca
עברית: אמוניה
Basa Jawa: Amonia
ಕನ್ನಡ: ಅಮೊನಿಯ
ქართული: ამიაკი
қазақша: Аммиак
Kiswahili: Amonia
kurdî: Amonyak
Кыргызча: Аммиак
Latina: Ammonia
latviešu: Amonjaks
lietuvių: Amoniakas
Limburgs: Ammoniak
magyar: Ammónia
македонски: Амонијак
മലയാളം: അമോണിയ
मराठी: अमोनिया
Bahasa Melayu: Ammonia
монгол: Аммиак
မြန်မာဘာသာ: အမ်မိုးနီးယား
Nederlands: Ammoniak
नेपाली: तिक्ताति
日本語: アンモニア
norsk: Ammoniakk
norsk nynorsk: Ammoniakk
occitan: Amoniac
oʻzbekcha/ўзбекча: Ammiak
ਪੰਜਾਬੀ: ਅਮੋਨੀਆ
پنجابی: امونیا
Piemontèis: Amonìa
Plattdüütsch: Ammoniak
polski: Amoniak
português: Amoníaco
română: Amoniac
русский: Аммиак
Scots: Ammonia
shqip: Amoniaku
sicilianu: Ammunìaca
Simple English: Ammonia
سنڌي: امونيا
slovenčina: Amoniak
slovenščina: Amonijak
српски / srpski: Амонијак
srpskohrvatski / српскохрватски: Amonijak
Basa Sunda: Amonia
suomi: Ammoniakki
svenska: Ammoniak
Tagalog: Amonya
தமிழ்: அமோனியா
తెలుగు: అమ్మోనియా
тоҷикӣ: Аммиак
Türkçe: Amonyak
українська: Аміак
اردو: امونیا
Tiếng Việt: Amoniac
Winaray: Amonya
ייִדיש: אמאניאק
Yorùbá: Ammonia