Can Oxygen Labeling Prove the Esterification Reaction Mechanism in P&D Lab?

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The discussion revolves around testing the esterification reaction mechanism between ethanol and ethanoic acid, specifically focusing on the role of the -OH group from the acid. A proposed hypothesis involves labeling the oxygen in either reactant with O-18 to trace its incorporation into the ester product. The suggested experimental design includes reacting the labeled compounds, extracting the ester, and analyzing it using mass spectrometry. Concerns arise regarding the separation of the ester from water, with suggestions of using pipetting or steam distillation, though the latter is cautioned against in acidic or basic conditions. Ultimately, the discussion emphasizes the importance of proper extraction techniques for accurate analysis.
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Homework Statement


Some students had a disagreement about the esterification reaction between ethanol and ethanoic acid. Student A feels that the -OH group from the acid combines with the H from the alcohol functional group.
Suggest a hypothesis for his feeling and design a lab to test the hypothesis.

Homework Equations



C_2H_5OH + CH_3COOH \rightarrow CH_3COOC_2H_5 + H_2O

The Attempt at a Solution



Ok, well my idea would be to somehow label the oxygen on either the acid or the alcohol. I chose O-18. But I am not sure what steps are taken to actually label the oxygen like that.
Then react the two, extract the ester formed, and run it through a mass spectrometer. But when the ester is formed, it is formed in a layer with water,how do I separate the two? (Simple pipette and extract until it looks like all has been pipetted?)
 
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rock.freak667 said:

Homework Statement


Some students had a disagreement about the esterification reaction between ethanol and ethanoic acid. Student A feels that the -OH group from the acid combines with the H from the alcohol functional group.
Suggest a hypothesis for his feeling and design a lab to test the hypothesis.

Homework Equations



C_2H_5OH + CH_3COOH \rightarrow CH_3COOC_2H_5 + H_2O

The Attempt at a Solution



Ok, well my idea would be to somehow label the oxygen on either the acid or the alcohol. I chose O-18. But I am not sure what steps are taken to actually label the oxygen like that.

You can buy O-18 labelled water. Any help?

Then react the two, extract the ester formed, and run it through a mass spectrometer. But when the ester is formed, it is formed in a layer with water,how do I separate the two? (Simple pipette and extract until it looks like all has been pipetted?)
If you injected it into a GC-MS you wouldn't have to separate anything...
 
Ah well all I need to say is that I labelled the oxygen. So no need to elaborate on it.
But apparently I must use the normal mass spec. I know so I would need to extract it somehow. I'm thinking steam distillation.
 
rock.freak667 said:
I'm thinking steam distillation.
Not a good idea in the presence of either an acid or base. Maybe diluting in solvent and drying with Na2SO4 after washing with bicarb.
 
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