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Hydration is an important process in many other applications; one example is the production of Portland cement by the crosslinking of calcium oxides and silicates that is induced by water. Hydration is the process by which desiccants function. CuSO 4 ·5H 2 O is bright blue and has a rather different structure from its colourless anhydrous ...
Some mineral structures, for example, montmorillonite, are capable of including a variable amount of water without significant change to the mineral structure. [citation needed] Hydration is the mechanism by which hydraulic binders such as Portland cement develop strength. A hydraulic binder is a material that can set and harden submerged in ...
For example: ethanol, CH 3 −CH 2 −OH, is the product of the hydration reaction of ethene, CH 2 =CH 2, formed by the addition of H to one C and OH to the other C, and so can be considered as the hydrate of ethene. A molecule of water may be eliminated, for example, by the action of sulfuric acid.
Mineral hydration is a form of chemical weathering that involves the rigid attachment of water molecules or H+ and OH- ions to the atoms and molecules of a mineral. No significant dissolution takes place. For example, iron oxides are converted to iron hydroxides and the hydration of anhydrite forms gypsum. [38]
The hydration reaction of acetylene gives acetaldehyde. The reaction proceeds by formation of vinyl alcohol, which tautomerizes to form the aldehyde. This reaction was once a major industrial process but it has been displaced by the Wacker process. This reaction occurs in nature, the catalyst being acetylene hydratase.
Notable examples of hydrolysis are the saponification of fats and the digestion of proteins and polysaccharides. Water can also be a leaving group in S N 2 substitution and E2 elimination reactions; the latter is then known as a dehydration reaction.
Metasomatism (from the Greek μετά metá "change" and σῶμα sôma "body") is the chemical alteration of a rock by hydrothermal and other fluids. [1] It is traditionally defined as metamorphism which involves a change in the chemical composition, excluding volatile components. [2]
Chemical reactions digest the minerals of the protolith which yields new minerals. This is a very slow process as it can also involve the diffusion of atoms through solid crystals. [22] An example of a neocrystallization reaction is the reaction of fayalite with plagioclase at elevated pressure and temperature to form garnet. The reaction is: [23]