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Sodium hydroxide, also known as lye and caustic soda, [1] [2] is an inorganic compound with the formula NaOH.It is a white solid ionic compound consisting of sodium cations Na + and hydroxide anions OH −.
The volume of a particular material or compound is affected by ambient moisture and may be considered its coefficient of hygroscopic expansion (CHE) (also referred to as CME, or coefficient of moisture expansion) or the coefficient of hygroscopic contraction (CHC)—the difference between the two terms being a difference in sign convention.
Glass disease, also referred to as sick glass or glass illness, is a degradation process of glass that can result in weeping, crizzling, spalling, cracking and fragmentation. [ 1 ] [ 2 ] Glass disease is caused by an inherent instability in the chemical composition of the original glass formula. [ 3 ]
Also acid ionization constant or acidity constant. A quantitative measure of the strength of an acid in solution expressed as an equilibrium constant for a chemical dissociation reaction in the context of acid-base reactions. It is often given as its base-10 cologarithm, p K a. acid–base extraction A chemical reaction in which chemical species are separated from other acids and bases. acid ...
Similarly, potassium hydroxide is available as a solution used for cleaning terraces and other areas made out of wood. Both NaOH and KOH are also used in the production of soap and detergents (saponification). Due to their hygroscopic properties, alkali hydroxides are used as desiccants.
Without the presence of dissolved NaOH or KOH, responsible for the high pH (~13.5) of the concrete pore water, the amorphous silica of the reactive aggregates would not be dissolved and the reaction would not evolve. Moreover, the soluble sodium or potassium silicate is very hygroscopic and swells when it absorbs water.
Lead oxide is the traditional low temperature flux used for crystal glass, but it is now avoided because it is toxic even in small quantities. It is being replaced by other substances, especially boron and zinc oxides. [3] In clay bodies a flux creates a limited and controlled amount of glass, which works to cement crystalline phases together.
Crude versions of conically tapered ground glass joints have been made for quite a while, [1] particularly for stoppers for glass bottles and retorts. [2] Crude glass joints could still be made to seal well by grinding the two parts of a joint against each other using an abrasive grit, but this led to variations between joints and they would not seal well if mated to a different joint.