6. 請將以下各為 0.10 M 的溶液由 pH 值低到高排列 :NaF,NaC2H3O2,C5H5NHCl, KOH,HCN (HCN: Ka = 6.2 × 10–10; HF: Ka = 7.2 × 10–4 ; HC2H3O2: Ka = 1.8 × 10–5 ; C5H5N: Kb =1.7 × 10–9 ) (A) C5H5NHCl, HCN, NaF, NaC2H3O2, KOH (B) NaF, NaC2H3O2, HCN, C5H5NHCl, KOH (C) KOH, NaC2H3O2, NaF, HCN, C5H5NHCl (D) HCN, C5H5NHCl, NaF, NaC2H3O2, KOH