試題詳解

5. 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)171g/mol
(C)165 g/mol
(D) 151 gmol
(E) 82.7gmol