K_2Cr_2O_7法测定Fe^(2+)实验微型化研究

Study on determination of Fe^(2+) using K_2Cr_2O_7 titration experimental miniaturization

借助改装的微量滴定管,考察了K2Cr2O7法测定亚铁盐样品中Fe2+实验微型化的可行性及较佳浓度范围.在不改变基本操作的前提下,借助F检验和t检验,通过与常量法比较发现,当试剂用量减少为常量法的1/5时,该实验的精密度有所下降,但仍能基本满足学生实验的要求.微量法所用K2Cr2O7标液的较佳浓度范围为0.009 4~0.034 0 mol/L.

The feasibility and the range of concentration in the miniaturization experiment about the Fe2＋content of the ferrous salt was studied through using adapted micro type burette. Keeping the basic operation, using F-test and t test, comparing with constants titration, when reagent consumption reduced to 1/5, the precision declined, but it can still basically meet the students＇ experiment requirement. The preferred concentration range for standard solution of K2Cr2O7 is 0.009 4-0.034 0 mol/L.