[madscientist]

Im looking at a reaction i did which involved the protonation of a
sodium salt of a beta-keto acid.  The reaction scheme is shown below.  I diluted some concentrated sulfuric acid and used this for the protonation step, what's got me puzzled is I cant figure out if its the sulfuric acid that directly protonates the beta-keto acid or whether it involves the formation of a hydronium ion when i diluted the sulfuric acid with water and whether it is this hydronium ion that protonates the beta-keto acid.

In short was it the sulfuric acid that supplied the hydrogen or a hydronium ion?

And what happens to the sodium?

[Yggdrasil]

If you put sulfuric acid in water, you no longer have sulfuric acid; you have hydronium ions, bisulfate ions, and sulfate ions since sulfuric acid will dissociate completely.

The sodium ions stay in solution and act as a counter ion to the bisulfate and sulfate ions.

[madscientist]

Thanks Yggdrasil,