Chemical Forums
Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Absinthcloud on November 18, 2007, 04:31:34 PM
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After attending my most recent Organic Chemistry lab titled "Reactions of aldehydes and Ketones" I am left with two unknowns (about 2 mL liquid each) that I have removed from the class because I was not able to correctly identify them. The Laboratory involved testing some common aldehyde and ketons such as Acetone, Cyclohexanone, Benzaldehyde, Toluene, and two unknowns. with reagents such as: Chromic Acid, Tollens reagent, Schiffs Reagent, Iodoform and 2,4-Dinitrophenylhydrazine. After completing all the reactions The two unknowns looked as if the mirrored Acetone AND Cyclohexanone. Due to time constraints I was unable to due further testing.. As stated above I now have a few mL's of the two unknows at home... Can anyhow tell me if there is any way to properly differentiate between these two compounds from my home??
Thanks in advance!!!
Daniel
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Either density or boiling point should clearly distinguish the two. Or if you have lab access run the iodoform classification test for methyl ketones.
http://en.wikipedia.org/wiki/Iodoform_test#Iodoform_reaction
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So The iodoform for methyl ketone test should only be positive with the Acetone not the Cyclohexanone correct? The hard part for me is to get the lab access to attempt this. Is Anything I could try out of the lab.. I mean using anything I could obtain from local stores???
Thanks for the Reply!
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Either density or boiling point should clearly distinguish the two.
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Is cyclohexanone very soluble in water (wikipedia states it is "slightly soluble")? Acetone is miscible with water...
Also, if you drop a small amount of acetone on a counter or some such, and lightly blow on it/pass air over it, it should quickly evaporate...
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macman104 is right!
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Acetone will dissolve and remove nail polish cyclohexane will just get messy.
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Could this one be done by smell? I know the smell of acetone quite well - I presume cyclohexanone will not be exactly the same - internet says it is similar to acetone but with a peppermint odour. Thus - if you smell them both - the pepperminty smelling one will be the cyclohexanone.
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Open bottles - acetone has lower boiling point and dissapers faster (of course samples should be approx. the same, also bottles)