后酒子大宝 Shihezi University 酸度：pH6.5~10.0; 有NH存在：pH6.5-7.2 H++Cr042-台Cr202(K=4.3X1014) pH>6.5 酸性过强，导致CO2]降低，终点滞后 pH=4.0? 碱性太强： Ag20沉淀 pH<10.0 Agt+nNH3Ag(NH3) pH<7.2 NH3+H+台NL 酸度：pH 6.5 ~ 10.0 pH 6.5 ~ 10.0 pH 6.5 ~ 10.0 pH 6.5 ~ 10.0 pH 6.5 ~ 10.0 pH 6.5 ~ 10.0 pH 6.5 ~ 10.0 pH 6.5 ~ 10.0； 有NH33存在：pH 6.5 ~7.2 pH 6.5 ~7.2 pH 6.5 ~7.2 pH 6.5 ~7.2 pH 6.5 ~7.2 pH 6.5 ~7.2 pH 6.5 ~7.2 pH 6.5 ~7.2 H+++CrO44 2-2-� Cr22O77 2- 2-(K=4.3×101414) 碱性太强： Ag22O 沉淀 pH> 6.5 pH> 6.5 pH> 6.5 pH> 6.5 pH> 6.5 pH> 6.5 pH> 6.5 pH> 6.5 酸性过强，导致 酸性过强，导致[CrO44 2-2-]降低，终点滞后 降低，终点滞后 pH< 10.0 pH< 10.0 pH< 10.0 pH< 10.0 pH< 10.0 pH< 10.0 pH< 10.0 pH< 10.0 Ag+++ nNH3 3 � Ag(NH33)n n pH< 7.2 pH< 7.2 pH< 7.2 pH< 7.2 pH< 7.2 pH< 7.2 pH< 7.2 pH< 7.2 NH3 3+ H++� NH44 ++ pH= 4.0 pH= 4.0 pH= 4.0 pH= 4.0 pH= 4.0 pH= 4.0 pH= 4.0 pH= 4.0？