[ethan]

Depending on the details of the mechanism (molecular pathway) of the reaction between salicylic acid and acetic anhydride, the oxygen atom connected to the benzene ring in the product, aspirin, could conceivably have been part of the original salicylic acid molecule or the acetic anhydride molecule.  Can you devise an experiment to determine which is the case? (Hint: How can a particular atom in the structure of a molecule be distingushed from other atoms of the same element in the same molecule?)

Do I do something with the Kolbe Schmitt Reaction? I really have no idea with this question. Its like an optional question but it will bother me if I can't think of something for it...I need someone to guide me

[Borek]

Why molar masses are not integer numbers?

[ethan]

How can a particular atom in the structure of a molecule be distingushed from other atoms of the same element in the same molecule?

Can anyone think of any type of experiment I could perform during the aspirin synthesis to distinguished the single Oxygen atom on the benzene ring and then find out if it came from the acetyl anhydride or salicylic acid?

[Arkcon]

How can a particular atom in the structure of a molecule be distingushed from other atoms of the same element in the same molecule?

There is a way, many of us have hinted at it.  What you want to do, is attach sole sort of label to a particular atom, can you think of a way?

Can anyone think of any type of experiment I could perform during the aspirin synthesis to distinguished the single Oxygen atom on the benzene ring and then find out if it came from the acetyl anhydride or salicylic acid?

I've not been working that angle in this discussion.  Do you have a way, 'cause I'm drawing a blank on that method.

[ARGOS++]

Dear Ethan;

Coming back to the Gravity of “real” Live (It’s maybe the first Time!) :

You may think about:  What would happen in one or the other case for the Product, if you would use (It was already done.) the carbone acid anhydride with marked Oxygen?
It means, that you use an other then the “usual” Isotope of Oxygen for it!

Good Luck!
                    ARGOS⁺⁺

[ARGOS++]

Dear Mr. Borek;

Thank you!,  ─  That looks very powerful!
(But I will keep the whole for Documentation.)

Kind Regards!
                            ARGOS⁺⁺