Potassium hydrogen phthalate (KHC8H4O4, molar mass 204.2 g/mol) is frequently used to standardize solutions of NaOH. The reaction is:
NaOH(aq) + KHC8H4O4(aq) --> H2O(l) + NaKC8H4O4(aq)
Calculate the mass of potassium hydrogen phthalate needed to react with 30 mL of 0.10 M NaOH.