試卷名稱:113年 - 113 學士後醫學系招生考試:物理及化學#119747
年份:113年
科目:學士後西醫物理及化學
81. The pH of a bottle of vinegar is 2.75 at 25℃. What is the mass percentage concentration (w/w) of acetic acid in this vinegar, assuming no other acid is presented? (Ka of acetic acid: 1.8x10-5; pKa of acetic acid: 4.74; 10-2.75 = 0.0018; 102.75 = 562.3; assuming the density of vinegar = 1 g/cm3 ; CH3COOH=60 g/mol)
(A) 5.0%
(B) 4.0%
(C) 3.0%
(D) 2.0%
(E) 1.0%