Simple O-Chem question

[Char. Limit]

1. The problem statement, all variables and given/known data
In the compound Glycolic Acid, with the structure below:

http://upload.wikimedia.org/wikipedia/commons/thumb/6/6d/Glycolic_acid.svg/120px-Glycolic_acid.svg.png

Which hydrogen will get removed in an acid-base reaction first?

3. The attempt at a solution

I figure that it would be the carboxylic hydrogen, rather than the alcohol hydrogen, but I can't be completely certain, and I don't like not being completely certain.

So... am I right?

[Borek]

Yes.

[Char. Limit]

All right, thanks. Now I can finish this chem homework.

[Ygggdrasil]

The reason why the carboxylic hydrogen is more acidic than the hydroxyl hydrogen is that the carboxylate group that results when the hydrogen is removed carboxylic acid undergoes resonance stabilization. No such resonance stabilizes the hydroxide group that results from the deprotonation of the hydroxyl.