BCH370H1 Study Guide - Midterm Guide: Reagent, Tryptophan, Absorbance
Document Summary
Can be used to compare acids and buffers. Used to determine amount of ionization for weak acids and bases. Assuming [ha] is amount of total acid added for weak acids. When ph < pka then there are more protons and so more [ha] When ph > pka then there are less protons and so more [a-] When ph = pka then there are equal levels of [ha] and [a-] Isoelectric point (pi): ph at which net charge is neutral; determined by taking the average of the two pkas around the neutral point. First buffer zone at inflection point of the titration against acid; Equal concentrations of zwitterion and fully protonated form. Both carboxyl group and amino group ionized: zwitterionic form. Second buffer zone at inflection point of titration against acid; equal concentrations of fully deprotonated form and zwitterion. Alanine has two pka values for each buffer region (b and d)