Alanine is a diprotic amino acid with a pK_a = 2.344 for the carboxylic group and a pK_a = 9.868 for the ammonium group.At pH = 6.32,what is the principal species in solution?

Question

Quizplus · Accepted Answer

At pH 6.32, the protonated carboxylic group has largely deprotonated and exists as COO-, and the ammonium group has mostly remained protonated and exists as NH3+. Therefore, the resulting species is HL, which represents alanine in a zwitterionic form.

Alanine Is a Diprotic Amino Acid with a PKa =

Alanine Is a Diprotic Amino Acid with a PK_a =