【简答题】A 100mL portion of a 0.1000mol·L -1 aqueous solution of the weak acid HA is extracted with 50.00mL of CCl 4 . After the extraction,a 25.00mL aliquot of the aqueous phase was titrated with 10.00mL of a...
【单选题】现有 50.00 mL 某二元酸 H 2 B (已知 c H2B =0.1000 mol · L -1 ),用 0.1000 mol · L -1 的 NaOH 溶液滴定。在加入 25.00 mL NaOH 溶液时, pH=4.80 ;加入 50.00 mL NaOH ,即在第一化学计量点时, pH=7.15 ,则 Ka 2 值为