Acetylation- acetic acid or acetic anhydride

[Taryn]

I did an experiment in one of the labs and I have a question I need to figure out.
The experiment was the porduction of p-acetylaminotoluene, from p-toluidine.
My question is we used acetic acid and acetic anhydride, but which is the acetyalting species.
I thought of looking at the structures of them but that kinda just confused me more.
I know that acetic anhydride is used to acetylate secondary and primary alcohols sometimes, but it gives a lower yield.
I got quite a high yield so I thought that the acetic acid might have been the acetylating species.

If anyone could just point me in the right direction that would be gr8. I am goin to ask my demonstrator today but any help would still be much appreciated.

 

[Nerro]

Have a look at the quantities of both chemicals you used, if that doesn't point you in the right direction post all the numbers here and I'll have a look at them for you.

 

[Taryn]

I used 4ml of acetic acid and 6ml of acetic anhydride.
I don't know how knowing how much I put in shows which is the acetylating species?

 

[chemisttree]

acetic acid is an acid and toluidine is an amine base. What happens when you combine an acid with a base?