試題詳解

2. 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. (Na: 22.99 g/mol)
(A) 247 g/mol；
(B) 171 g/mol；
(C) 165 g/mol；
(D) 151 g/mol；
(E) 82.7 g/mol