試題詳解

72. A 0.307-g sample of an unknown triprotic acid is titrated to the third equivalence point using 35.2 mL of 0.106 M NaOH. Calculate the molar mass of the acid.
(A) 247 g/mol
(B) 171 g/mol
(C) 165 g/mol
(D) 151 g/mol
(E) 82.7 g/mol