Dr.Bob,

Arrange these acids in terms of increasing acidity:
CH3COOH, NH3+CH2COOH, CH3CONHCH2COOH

According to my Chem textbook,NH3+CH2COOH has a low pKa value since both the COOH & NH3+ are protonated,so it is most acidic. CH3COOH is a weak acid, but I'm not sure about the N-acetylglycine.Dr.Bob said earlier that I had the order reversed,which means CH3COOH is most acidic among all three. Hope Dr.Bob can explain why my assumptions went wrong.
Thank you

3 answers

First, can you tell me what NH3+CH2COOH is. I have no idea. Is this a way of writing NH3 + CH3COOH for ammonium acetate. CH2COOH isn't anything is it?
Ok,that NH3+CH2COOH is obtained when 1 mol of glycine is added with a strong acid,which results in both amino & carboxyl groups to be fully protonated.
See my later post to your explanation. However, I think you get the amino group protonated; the carboxyl group is already fully protonated isn't it?