Drying Solvents - Revision history

Zakara at 03:19, 25 June 2012

2012-06-25T03:19:24Z

2012-06-25T03:17:08Z

2012-06-25T03:08:32Z

2012-06-25T00:50:34Z

2012-06-25T00:41:34Z

2012-06-24T23:32:13Z

2012-06-24T22:53:53Z

‎Common solvents with respective drying agents

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-. '''[[Solvents]] like''' ''[[acetonitrile]], [[dimethylsulfoxide]] (DMSO) and [[acetone]]'' can be dried with CaH2 and then distilled under inert gas. [[Acetonitrile]] and [[acetone]] can be dried over P4O10 to remove trace amounts of water. In the presence of larger amounts of water, these compounds form condensation products and have to be pre-dried with [[Calcium hydride]]. Other procedures involve the use of anhydrous [[magnesium sulfate]] (dimethyl formamide, DMF). The purified solvents should be stored under an inert atmosphere over molecular sieve.
+. '''Solvents like''' ''[[acetonitrile]], [[dimethylsulfoxide]] (DMSO) and [[acetone]]'' can be dried with CaH2 and then distilled under inert gas. [[Acetonitrile]] and [[acetone]] can be dried over P4O10 to remove trace amounts of water. In the presence of larger amounts of water, these compounds form condensation products and have to be pre-dried with [[Calcium hydride]]. Other procedures involve the use of anhydrous [[magnesium sulfate]] (dimethyl formamide, DMF). The purified solvents should be stored under an inert atmosphere over molecular sieve.
 [[Category:Laboratory Techniques]]
 [[Category:solvent]]

← Older revision		Revision as of 03:17, 25 June 2012
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−	3. '''[[Halogenated solvents]]''' ''([[~~CH2Cl2~~]], [[~~CHCl3~~]], [[~~CCl4~~]], [[~~C2Cl4~~]], [[~~C2Cl6~~]])'' can be dried over CaH2 or P4O10 after pretreatment with [[sulfuric acid]]. '''Never attempt to dry halogenated solvents with alkali metals or alkali metal hydrides!''' This will cause violent explosions due to a radical reaction! Whenever possible, these solvents should be replaced with non-halogenated solvents. The combustion of chlorinated solvents generates a high amount of dioxines.	+	3. '''[[Halogenated solvents]]''' ''([[Dichloromethane]], [[Chloroform]], [[Carbon tetrachloride]], [[Tetrachloroethylene]], [[Hexachloroethane]])'' can be dried over CaH2 or P4O10 after pretreatment with [[sulfuric acid]]. '''Never attempt to dry halogenated solvents with alkali metals or alkali metal hydrides!''' This will cause violent explosions due to a radical reaction! Whenever possible, these solvents should be replaced with non-halogenated solvents. The combustion of chlorinated solvents generates a high amount of dioxines.

← Older revision		Revision as of 03:08, 25 June 2012
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−	4. '''[[Alcohols]]'''can also be dried with ''CaH2''. There are several special procedures for various alcohols e.g. ''[[ethanol]]'' can be dried with ''sodium metal/phthalic acid diethyl ester.''	+	4. '''[[Alcohols]]''' can also be dried with ''CaH2''. There are several special procedures for various alcohols e.g. ''[[ethanol]]'' can be dried with ''sodium metal/phthalic acid diethyl ester.''

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 . '''[[Solvents]] like''' ''[[acetonitrile]], [[dimethylsulfoxide]] (DMSO) and [[acetone]]'' can be dried with CaH2 and then distilled under inert gas. [[Acetonitrile]] and [[acetone]] can be dried over P4O10 to remove trace amounts of water. In the presence of larger amounts of water, these compounds form condensation products and have to be pre-dried with [[Calcium hydride]]. Other procedures involve the use of anhydrous [[magnesium sulfate]] (dimethyl formamide, DMF). The purified solvents should be stored under an inert atmosphere over molecular sieve.
-[[Category:laboratory techniques]]
+[[Category:Laboratory Techniques]]
 [[Category:solvent]]

← Older revision		Revision as of 00:41, 25 June 2012
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	5. '''[[Solvents]] like''' ''[[acetonitrile]], [[dimethylsulfoxide]] (DMSO) and [[acetone]]'' can be dried with CaH2 and then distilled under inert gas. [[Acetonitrile]] and [[acetone]] can be dried over P4O10 to remove trace amounts of water. In the presence of larger amounts of water, these compounds form condensation products and have to be pre-dried with [[Calcium hydride]]. Other procedures involve the use of anhydrous [[magnesium sulfate]] (dimethyl formamide, DMF). The purified solvents should be stored under an inert atmosphere over molecular sieve.		5. '''[[Solvents]] like''' ''[[acetonitrile]], [[dimethylsulfoxide]] (DMSO) and [[acetone]]'' can be dried with CaH2 and then distilled under inert gas. [[Acetonitrile]] and [[acetone]] can be dried over P4O10 to remove trace amounts of water. In the presence of larger amounts of water, these compounds form condensation products and have to be pre-dried with [[Calcium hydride]]. Other procedures involve the use of anhydrous [[magnesium sulfate]] (dimethyl formamide, DMF). The purified solvents should be stored under an inert atmosphere over molecular sieve.

−	[[Category:~~Drying Solvents~~]]	+	[[Category:laboratory techniques]]
		+	[[Category:solvent]]

← Older revision		Revision as of 23:32, 24 June 2012
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	5. '''[[Solvents]] like''' ''[[acetonitrile]], [[dimethylsulfoxide]] (DMSO) and [[acetone]]'' can be dried with CaH2 and then distilled under inert gas. [[Acetonitrile]] and [[acetone]] can be dried over P4O10 to remove trace amounts of water. In the presence of larger amounts of water, these compounds form condensation products and have to be pre-dried with [[Calcium hydride]]. Other procedures involve the use of anhydrous [[magnesium sulfate]] (dimethyl formamide, DMF). The purified solvents should be stored under an inert atmosphere over molecular sieve.		5. '''[[Solvents]] like''' ''[[acetonitrile]], [[dimethylsulfoxide]] (DMSO) and [[acetone]]'' can be dried with CaH2 and then distilled under inert gas. [[Acetonitrile]] and [[acetone]] can be dried over P4O10 to remove trace amounts of water. In the presence of larger amounts of water, these compounds form condensation products and have to be pre-dried with [[Calcium hydride]]. Other procedures involve the use of anhydrous [[magnesium sulfate]] (dimethyl formamide, DMF). The purified solvents should be stored under an inert atmosphere over molecular sieve.
		+
		+	[[Category:Drying Solvents]]

← Older revision		Revision as of 22:53, 24 June 2012
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−	2. '''[[Hydrocarbons]]''' like ''[[pentane]]'', ''[[hexane]]'', ''[[cyclohexane]]'', ''[[benzene]]'', ''[[toluene]]'' are another important class of solvents. These solvents are generally not as hygroscopic as ethers, but often contain unsaturated compounds that have to be removed by washing the solvent with concentrated [[sulfuric acid]]. After removing the acid, they can be ~~died~~ over CaH2 or sodium metal, depending on the quality needed. For most purposes, several hours of reflux, follow by a distillation under inert gas is sufficient. If possible, the use of benzene should be avoided due to its carcinogenic effect.	+	2. '''[[Hydrocarbons]]''' like ''[[pentane]]'', ''[[hexane]]'', ''[[cyclohexane]]'', ''[[benzene]]'', ''[[toluene]]'' are another important class of solvents. These solvents are generally not as hygroscopic as ethers, but often contain unsaturated compounds that have to be removed by washing the solvent with concentrated [[sulfuric acid]]. After removing the acid, they can be dried over CaH2 or sodium metal, depending on the quality needed. For most purposes, several hours of reflux, follow by a distillation under inert gas is sufficient. If possible, the use of benzene should be avoided due to its carcinogenic effect.