alkali

Traductions

• anglais

  Date : 1990

  Définition

  A substance which is soluble in water to form a solution and is capable of neutralising an acid.

  Notes :

  This term is normally used to refer to hydroxides and carbonates of the metals of group IA of the periodic table, as well as to ammonium hydroxide. All are bases, and their aqueous solutions range in pH from 7 to 13. Strong alkalis are also called caustics, their solutions being corrosive to the skin and other tissues.
  
  Alkali deposits occur widely in the American desert, and are either surface-mined or recovered from salt lakes. Very large tonnages of sodium carbonate in the form of trona, Na₂CO₃.NaHCO₃.2H₂O, are mined from underground deposits in Wyoming. Most alkali hydroxides are made by electrolysis of alkali chloride solutions, e.g., sodium hydroxide (NaOH) from sodium chloride (NaCl) and potassium hydroxide (KOH) from potassium chloride (KCl).

  Terme :

  1. alkali