This document describes the process and calculations for determining the molar mass and ionization constant of a weak monoprotic acid. Two trials were conducted where the pH and volume of an acetic acid solution was measured before and after titration with a standardized NaOH solution. The moles of acetic acid and NaOH were calculated from the titration data. This was used to calculate the molar concentration, molar mass, and ionization constant of acetic acid.