Why do we use 4 molar HCl in the preparation of hydrochloride salt of amino acids?

For example if we have L-alanine and we want to convert it to L-alanine monohydrochloride, we have to add 4 M (as a concentration) of HCl acid. Why 4M no more or less?

09 September 2014 9,061 1 View