#hydroxide

• Alkali — A generic name given to the hydroxides of alkali metals (such as sodium, potassium) and alkaline earth metals, as well as ammonium hydroxide. In a traditional chemical sense, it refers to any water-soluble base capable of neutralizing acids, turning red litmus paper blue, and forming salts through combination reactions.
• 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.
• Alkali cellulose — An intermediate product obtained in the chemical industry by treating cellulose with a concentrated solution of sodium hydroxide (caustic soda). This compound plays an essential structural role in the manufacture of viscose, rayon, and cellophane, facilitating the subsequent chemical reactivity of fibers by altering the macromolecular molecular arrangement.
• Amphoteric — Describing substances, oxides, or hydroxides: exhibiting a chemical duality, having the capacity to behave either as an acid in the presence of a strong base or as a base in the presence of a strong acid. This structural character depends directly on the pH of the reaction medium and allows the formation of salts in both biochemical contexts.
• 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.