This article is about chemical reactions resulting in the loss of water from a molecule. For the removal of water from solvents and reagents, see Desiccation. Show
In chemistry, a dehydration reaction is a chemical reaction that involves the loss of water from the reacting molecule or ion. Dehydration reactions are common processes, the reverse of a hydration reaction. Dehydration reactions in organic chemistry[edit]Esterification[edit]The classic example of a dehydration reaction is the Fischer esterification, which involves treating a carboxylic acid with an alcohol to give an ester Often such reactions require the presence of a dehydrating agent, i.e. a substance that reacts with water. Etherification[edit]Two monosaccharides, such as glucose and fructose, can be joined together (to form saccharose) using dehydration synthesis. The new molecule, consisting of two monosaccharides, is called a disaccharide. Nitrile formation[edit]Nitriles are often prepared by dehydration of primary amides. Ketene formation[edit]Ketene is produced by heating acetic acid and trapping the product:[1] CH3CO2H → CH2=C=O + H2OAlkene formation[edit]Alkenes can be made from alcohols by dehydration. This conversion, among others, is a key reaction in converting biomass to liquid fuels.[2] The conversion of ethanol to ethene is a fundamental example:[3][4] CH3CH2OH → H2C=CH2 + H2OThe reaction is slow in the absence of an acid catalysts such as sulfuric acid and certain zeolites. Some alcohols are prone to dehydration. 3-Hydroxylcarbonyls, called aldols, release water upon standing at room temperature: RC(O)CH2CH(OH)R' → RC(O)CH=CHR' + H2OIn the dienol benzene rearrangement, dehydration leads to aromatization.[5][6] Often the reaction is induced by dehydrating reagents. For example, 2-methyl-cyclohexan-1-ol dehydrates to 1-methylcyclohexene in the presence of Martin's sulfurane, which reacts irreversibly with water.[7][8]  Double dehydration is illustrated by the conversion of glycerol to acrolein:[9][10] Dehydration reactions in inorganic chemistry[edit]The formation of the pyrophosphate bond is an important dehydration relevant to bioenergetics. Various construction materials are produced by dehydration. Plaster of Paris is produced by dehydration of gypsum in a kiln:[11][12] heat (released as steam).The resulting dry powder is ready to be mixed with water to form a stiff but workable paste that hardens. See also[edit]
References[edit]
What is dehydration explain with example?A dehydration reaction is a chemical reaction between two compounds where one of the products is water. For example, two monomers may react where a hydrogen (H) from one monomer binds to a hydroxyl group (OH) from the other monomer to form a dimer and a water molecule (H2O).
What is hydration and dehydration in chemistry?In chemistry, a dehydration reaction is a chemical reaction that involves the loss of water from the reacting molecule or ion. Dehydration reactions are common processes, the reverse of a hydration reaction.
What is the process dehydration?Dehydration is the process of complete removal of water from the fixed tissue. Dehydrating agents must be water soluble, and among them ethanol is the most widely used.
What type of organic reaction is dehydration?Dehydration reaction results in the formation of a covalent bond. Therefore, it is a type of condensation reaction. Thus, water is a common byproduct of condensation reactions in biological systems. A common example of dehydration reactions is the formation of ethers from the condensation of alcohols.
|
What is dehydration in organic Chemistry
direito autoral © 2024 cumeu Inc.
