Lhydroxyde

L'hydroxyde (French for hydroxide) denotes the hydroxide ion (OH−) and, more broadly, any compound that contains the hydroxide group. The hydroxide ion is formed when water loses a proton and is a key species in basic and hydrolysis reactions. In aqueous solutions, hydroxides confer basicity and can participate in neutralization reactions with acids to form water and a salt.

Common hydroxide compounds range from highly soluble bases such as sodium hydroxide (NaOH) to insoluble hydroxides such as calcium hydroxide (Ca(OH)2) and magnesium hydroxide (Mg(OH)2). Solubility and basic strength vary widely; strong bases dissociate completely in water, while some hydroxides are poorly soluble and act as heterogeneous bases.

Industrial production of hydroxides often involves processing metal oxides or salts. For example, lime slaking produces Ca(OH)2, and the chlor-alkali process yields NaOH from brine. Natural occurrences include minerals like brucite (Mg(OH)2) and gibbsite (Al(OH)3), though many hydroxides are primarily synthetic.

Uses span chemistry, manufacturing, and environmental applications. Hydroxides are used in neutralization of acids, paper production, water treatment, cement and construction (calcium hydroxide in lime). They also serve as catalysts or reagents in organic syntheses and as drying agents in various industries.

Safety and handling: hydroxides are caustic and can cause severe chemical burns. Protective equipment and proper storage are advised, with disposal following local regulations for caustic substances.