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Weigh the empty crucible that the sample is to be placed in and record its weight in a lab book. Place the sample in the empty crucible and weigh the crucible again with the sample in it. The new weight minus the empty crucible weight is the sample's wet weight. Place the sample in the drying oven or blast furnace as required.
The ensuing reaction results in the cleavage of the ether or the ester into an alkyl iodide and respectively an alcohol or a carboxylic acid. Zeisel determination By heating this mixture, the gases are allowed to come into contact with a piece of paper higher up the test tube saturated with silver nitrate .
Demethylation often refers to cleavage of ethers, especially aryl ethers. [12]Historically, aryl methyl ethers, including natural products such as codeine (O-methylmorphine), have been demethylated by heating the substance in molten pyridine hydrochloride (melting point 144 °C (291 °F)) at 180 to 220 °C (356 to 428 °F), sometimes with excess hydrogen chloride, in a process known as the ...
Elution principle of column chromatography. In analytical and organic chemistry, elution is the process of extracting one material from another by washing with a solvent: washing of loaded ion-exchange resins to remove captured ions, or eluting proteins or other biopolymers from a gel electrophoresis or chromatography column.
Alkenes can be made from alcohols by dehydration. This conversion, among others, is used in converting biomass to liquid fuels. [2] The conversion of ethanol to ethylene is a fundamental example: [3] [4] CH 3 CH 2 OH → H 2 C=CH 2 + H 2 O. The reaction is accelerated by acid catalysts such as sulfuric acid and certain zeolites.
In accordance with an E2 elimination the reaction with t-butyl chloride results in a KIE of 2.3. The methyl chloride reaction (only S N 2 possible) on the other hand has a KIE of 0.85 consistent with a S N 2 reaction because in this reaction type the C-H bonds tighten in the transition state. The KIE's for the ethyl (0.99) and isopropyl (1.72 ...
Ether cleavage refers to chemical substitution reactions that lead to the cleavage of ethers. Due to the high chemical stability of ethers, the cleavage of the C-O bond is uncommon in the absence of specialized reagents or under extreme conditions. [1] [2] In organic chemistry, ether cleavage is an acid catalyzed nucleophilic substitution reaction.
A 1,2-Wittig rearrangement is a categorization of chemical reactions in organic chemistry, and consists of a 1,2-rearrangement of an ether with an alkyllithium compound. [1] The reaction is named for Nobel Prize winning chemist Georg Wittig. [2] [3] The intermediate is an alkoxy lithium salt, and the final product an alcohol.