Ammonia (NH₃) is a colorless, pungent, toxic gas that is highly soluble in water. It plays a crucial role in the chemical, agricultural, water treatment, and fertilizer industries. Ammonia is one of the most important base chemicals in the production chain of nitrogen-containing compounds and is available commercially in two primary forms: anhydrous ammonia (compressed gas) and aqueous ammonia (ammonium hydroxide solution).

Chemical Structure of Ammonia

Molecular Formula: NH₃
Molecular Geometry: Trigonal pyramidal
Bond Angle: Approximately 107.8°
Bonding Characteristics: One nitrogen atom bonded to three hydrogen atoms, with one lone pair of electrons on the nitrogen atom

Physical and Chemical Properties

Property	Description
State at Ambient Conditions	Gas (or liquefied under pressure)
Odor	Strong, sharp, irritating odor
Boiling Point	–33.34 °C
pH (1M aqueous solution)	Approximately 11.6
Water Solubility	Very high — 1 volume of water dissolves about 700 volumes of NH₃ gas
Solubility in Ethanol	Low

Applications of Ammonia

Agriculture

Production of nitrogen fertilizers such as urea, ammonium nitrate, and ammonium phosphate
Used for soil pH adjustment in acidic soils

Chemical Industry

Feedstock for the production of nitric acid, amines, nitrates, sodium amide, and other nitrogen-based compounds
Used in the synthesis of resins and various organic nitrogen compounds

Refining and Petrochemical Industries

Acts as a CO₂ absorbent in steam methane reforming (SMR) processes
Used in demulsification, gas scrubbing, and pollution control systems

Water and Wastewater Treatment

Removes heavy metal ions such as copper, nickel, and lead
Used for pH control and odor suppression of sulfur-containing compounds

Food and Pharmaceutical Industries

Limited use as a disinfectant and pH regulator
Intermediate for the production of ammonium bicarbonate (baking agent) and certain nitrogen-based pharmaceuticals

Refrigeration Industry

Used as a high-efficiency industrial refrigerant (R-717)
Offers excellent thermal performance in chillers and cold storage systems

Advantages of Ammonia

Cost-effective nitrogen source for fertilizer production
Highly efficient industrial refrigerant
Strong alkaline solution for water purification and heavy metal removal
Useful solvent and reactant in specialized chemical syntheses
Can be produced domestically via the Haber–Bosch process (from nitrogen and hydrogen gases)

Disadvantages of Ammonia

Highly toxic upon inhalation or skin contact
Flammable under certain conditions (at high concentrations in air)
Extremely pungent and irritating odor
Strongly corrosive in concentrated form
Requires specialized pressurized equipment for safe storage and handling

Safety and Handling of Ammonia

GHS Classification

H331: Toxic if inhaled
H314: Causes severe skin burns and eye damage

Personal Protective Equipment (PPE)

Respirator with ammonia-specific cartridge filter
Chemical-resistant gloves
Safety goggles and face shield
Proper ventilation is mandatory; use in enclosed spaces only with active exhaust systems

Fire and Explosion Hazards