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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Sis290025 on October 10, 2006, 12:11:02 AM

Title: Matching Mixture With Proper Solvent For Separation in Chromatography
Post by: Sis290025 on October 10, 2006, 12:11:02 AM

Each of the solvents given should effectively separate one of the following mixtures by TLC. Match
the appropriate solvent with the mixture that you would expect to separate well with that solvent.
Select your solvent from the following: hexane, methylene chloride, or acetone.
 

a.2-phenylethanol and acetophenone
b.bromobenzene and p-xylene
c.benzoic acid, 2,4-dinitrobenzoic acid, and 2,4,6-trinitrobenzoic acid


For part A, 2-phenylethanol (C8H10O) is an alcohol and acetophenone(C8H8O) is a ketone. Would the solvent methylene chloride be the solvent for this mixture? The alcohol has a higher polarity than the ketone. Both would be soluble in Cl2CH2?

B. Bromobenzene is a halogenated hydrocarbon and p-xylene is a hydrocarbon; both have weak polarity. Since they are very nonpolar, they will travel a greater distance from the solvent front. (A more polar solvent would cause their retention factors to be high.) Will hexane be suitable for this group?

C. All are carboxylic acids, the most polar organic group. Acetone, a polar solvent, would match?

Thank you.     

Title: Re: Matching Mixture With Proper Solvent For Separation in Chromatography
Post by: Sis290025 on October 11, 2006, 02:15:55 PM

Are any of my reasonings correct?

Thanks again.

Title: Re: Matching Mixture With Proper Solvent For Separation in Chromatography
Post by: chiralic on October 12, 2006, 02:50:38 AM

Please see my post on post "Thin Layer Chromatography Errors"

Chiralic