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Multi-solvent recrystallization relies on the crude product being soluble in one solvent, when it is heated to reflux, while being insoluble in a secondary solvent, regardless of the solvent's temperature. [6] The volume ratio between the first and second solvent is critical.
Recrystallization: In analytical and synthetic chemistry work, purchased reagents of doubtful purity may be recrystallised, e.g. dissolved in a very pure solvent, and then crystallized, and the crystals recovered, in order to improve and/or verify their purity.
1,4-Naphthoquinone or para-naphthoquinone is a quinone derived from naphthalene. It forms volatile yellow triclinic crystals and has a sharp odor similar to benzoquinone. It is almost insoluble in cold water, slightly soluble in petroleum ether, and more soluble in polar organic solvents. In alkaline solutions it produces a reddish-brown color ...
A naphthalene molecule can be viewed as the fusion of a pair of benzene rings. (In organic chemistry, rings are fused if they share two or more atoms.) As such, naphthalene is classified as a benzenoid polycyclic aromatic hydrocarbon (PAH). [19] The eight carbon atoms that are not shared by the two rings carry one hydrogen atom each.
In chemistry, fractional crystallization is a stage-wise separation technique that relies on the liquid–solid phase change. This technique fractionates via differences in crystallization temperature and enables the purification of multi-component mixtures, as long as none of the constituents can act as solvents to the others.
In this example, assuming a racemate (50:50 mix of enantiomers), then with a eutectic of 0.23, the maximum yield we can expect from system, via crystallization, is 35%. Diastereomeric recrystallisation is a method of chiral resolution of enantiomers from a racemic mixture.
For example, a dental amalgam is formed by combining particles of a metal, usually gold or silver, with mercury. In organic chemistry, trituration is a process used to purify crude chemical compounds containing soluble impurities. A solvent is chosen in which the desired product is insoluble and the undesired by-products are very soluble or ...
These chains fold together and form ordered regions called lamellae, which compose larger spheroidal structures named spherulites. [1] [2] Polymers can crystallize upon cooling from melting, mechanical stretching or solvent evaporation. Crystallization affects optical, mechanical, thermal and chemical properties of the polymer.