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Chemistry Forums for Students => Organic Chemistry Forum => Topic started by: Saydalii on January 26, 2010, 04:52:10 AM

Title: Creating a flow diagram for separating aspirin, acetaminophen, and sucrose
Post by: Saydalii on January 26, 2010, 04:52:10 AM

I am having a lot of trouble with a problem I have in a Org Chem Lab.

I figured I should try to get some more *delete me*

Here is the general question.

Acetaminophen is a weaker acid than carbonic acid (H2CO3), but aspirin is a stronger acid than carbonic acid. Prepare flow diagram showing a procedure that can be used to separate a mixture of sucrose, aspirin, and acetaminophen.

I was not sure if this meant I needed to use carbonic acid in some way or not. I didn't end up using it. I didn't even know if carbonic acid is something that can be used or not. (I thought it was just Hydrogen and CO2)

Here is my flow chart, at least the best I can make it in words

                                                 Acetaminophen, Sucrose, and Aspirin in top group

                                                             Mix with Dichloromethane, filter

                          Solid Residue                                                                    Filtrate

                          Contains Sucrose and Acetaminophen                                   Aspirin in Dichloromethane

                          Add Water, Filter                                                              Evaporate

Solid Residue                                   Filtrate                                                 Aspirin

Acetaminophen                                Sucrose in water

                                                    Vacuum filtration

                                                    Sucrose

Extremely sorry about the word graph.

I just don't have excel or any of the microsoft office apps working on my computer

Firstly I saw that acetaminophen and sucrose is insoluble in dichloromethane, so I used that to separate the aspirin, with the dichloromethane be evaporated since it's boiling point is lower than aspirins.

I poured out the dichloromethane with aspirin into a beaker to separate the solid residue of acetaminophen and sucrose.

Allowed the small amount of dichloromethane to evaporate from the solid acetaminophen/sucrose residue.

I then added H2O to the solid residue, thinking that the sucrose is much more soluble in water than acetaminophen, then poured out the water with sucrose (and small amount of acetaminophen to) into another beaker, leaving the solid acetaminophen.

Then used vacuum filtration to filter out the solid sucrose.



I hope that helped a little bit
 
Please be harsh, I'm sure there are many errors in this. Please point them out to me and point out what are better ways to separate aspirin, sucrose, and acetaminophen.

Thank you so much for any help.

Saydalii

Title: Re: Creating a flow diagram for separating aspirin, acetaminophen, and sucrose
Post by: akcapr on January 27, 2010, 01:35:49 AM

to separate the sucrose and acetaminophen, try recrystallization. the first step for the aspirin. also, you could try an extraction to seperate acetaminophen from aspirin. aspirin has a significantly larger pka, so basifying to a ph approx. 11, since its pkb is around there, would probly work well.