Ammonia

Here are some key facts about ammonia:

1. Physical Properties:
   • Appearance: Ammonia is a colourless gas with a strong pungent odour.
   • Density: It is lighter than air, with a density approximately 589 times that of air.
   • Melting Point: The melting point of ammonia is -77.73°C.
   • Boiling Point: The boiling point of ammonia is -33.34°C.
   • Solubility: Ammonia is highly soluble in water, with a solubility of 530 g/L at 20°C and 320 g/L at 25°C¹.
2. Chemical Properties:
   • Acidity: Ammonia has a pKa value of 5 at -33°C.
   • Basicity: Its pKb value is 75.
   • Conjugate Acid: The conjugate acid of ammonia is ammonium.
   • Conjugate Base: The conjugate base of ammonia is amide.
   • Magnetic Susceptibility: The magnetic susceptibility of ammonia is -18.0 × 10⁻⁶ cm³/mol¹.
3. Uses:
   • Ammonia serves as a starting material for the production of various commercially important nitrogen compounds.
   • It is used in refrigeration as R717.
   • Liquid ammonia is a strong ionizing solvent that can dissolve alkali metals, forming colored, electrically conducting solutions³.
4. Hazards:
   • Ammonia is corrosive to some materials.
   • It has a lethal dose (LD50) of 350 mg/kg (rat, oral).
   • The gas is toxic and poses risks to human health¹.