Determination of An Unknown Amino Acid From Titration Experiment 11 used a titration curve to determine the identity of an unknown amino acid. The initial pH of the solution was 1.96, and the pKa’s found experimentally were 2.0, 4.0, and 9.85. The accepted pKa values were found to be 2.10, 4.07, and 9.47. The molecular weight was calculated to be 176.3 while the accepted value was found to be 183.5. The identity of the unknown amino acid was established to be glutamic acid, hydrochloride. Introduction Amino acids are simple monomers which are strung together to form polymers (also called proteins). These monomers ar