Analysis of Protonation Equilibria of Amino Acids in Aqueous Solutions Using Microsoft Excel

A Microsoft Excel workbook has been developed to simplify the quantitative analysis of experimentally measured titration curves for diprotic and triprotic amino acids such as glycine, arginine, histidine, glutamate. Students perform titration, enter data into worksheet, manually adjust resulting pKa values achieve closest agreement between experimental calculated curves. At same time, students can observe changes in speciation diagram that illustrates transitions differently protonated molecular species during titration. Through a combination graphical visualization analysis, supported by computer software, learn most important aspects protonation equilibria acid solutions. The knowledge gained serve basis understanding behavior more complex polyprotic aqueous solution residues proteins.