earloracion15-
Recrystallization
is one of the most important methods available for the purification of solids
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Recrystallization
It involves the preparation of a saturated solution of the organic compound in an appropriate solvent at an elevated temperature and filtering this solution while hot.
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Insoluble impurities
are removed during hot filtration
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animal charcoal
Colored impurities present in most organic substances may be removed by the addition of
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fluted filter paper
maximizes the flow rate during gravity filtration
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Supersaturated solution
A difficulty often encountered in recrystallization is the failure of the solute to crystallize. This is frequently due to too
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extensive inclusion in the cyrstals
rapid cooling causes
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Seeding
addition of a small crystal of the pure substance to induce crystallization.
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Scratching the inner walls of the glass
other way in order to form crystals
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Purity of the sample
The physical properties are dependent on the
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Melting point
is defined as the temperature at which the solid changes to liquid.
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Eutectic point
ia characteristic of mixture.
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Fisher johns or the Nalge Axelrod melting point apparatus
An alternative method of determining melting point is by the use of special equipment such as
