#ammonium hydroxide
- Volatile alkali — An archaic and historical designation used in chemistry and old pharmacy for ammonia (gas or an aqueous solution of ammonium hydroxide). The term highlights the substance's alkaline (basic) character and its pronounced capacity to evaporate rapidly at room temperature, releasing a strong, pungent, and suffocating odor.
- Ammonium hydroxide — An aqueous solution of ammonium hydroxide (NH₄OH), a clear, colorless liquid with a pungent, suffocating, and strongly alkaline odor, obtained by dissolving ammonia gas in water; it is widely used in the chemical industry as a laboratory reagent, in producing nitrogen fertilizers, cleaning agents, textiles, or as a refrigerant medium.