酸碱滴定终点误差计算法,徐海超,终点误差定义为：,在化学计量点时满足：,得质子产物 sp= 失质子产物sp,终点时：,强酸强碱的滴定,H+sp = OH-sp,以HCl滴定NaOH为例,化学计量点时：,终点时：,Cx = H+ep - OH-ep,H+sp = OH-sp +B-sp,化学计量点时：,Cx = H+ep - OH-ep - B-ep,Cx = H+ep - B-ep,忽略OH-ep,Cx = HPO42-sp1 -H+sp1 - H3PO4sp,多元酸碱,以NaOH滴定H3PO4为例,H+sp1 +H3PO4sp1 = OH-sp1 +HPO4-sp1 + 2PO43-sp1,化学计量点时：,忽略OH-， PO43-,H+sp = NH3 sp+ OH-sp,NaOH滴定HCl, NH4Cl混合溶液中的HCl,混合酸碱,化学计量点时：,Cx = NH3ep - H+ep,结论,写出化学计量点是的质子条件 做适当的忽略 将质子条件等式一边减去另一边得到 Cx，代入误差计算公式 根据相关条件几算出各形体浓度，从 而计算出滴定误差,H+ep + HB ep Caep = OH- ep Caep HB ep = H+ ep OH- ep Caep (CBep B- ep) = H+ ep OH- ep Caep CBep = H+ ep OH- ep B- ep,忽略 OH- ep,CX = Caep CBep = H+ ep B- ep,附：证明,浓度为Ca的强酸滴定浓度CB弱碱B-,