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以铁氰化钾为滴定剂的示波极谱滴定法称为铁氰化钾滴定法. 铁氰化钾溶液作为滴定剂具备很多优点:(1)铁氰化钾能得到很高的纯度,不吸湿,当量大,本身可作为基准物质.(2)铁氰化钾的水溶液很稳定,如避光保存,0.1mol·L~(-1)溶液五周内浓度不变.它的碱性溶液在较高温度下也很稳定.(3)铁氰化钾是一个比较弱的氧化剂,它具有强氧化剂所没有的选择性氧化性能.在盐酸中它能氧化Sn(Ⅱ)而不会氧化Mn(Ⅱ)与Cr(Ⅲ);它能将S_2O_4~(2-)氧化为SO_3~(2-)它能将N_3H_4氧化到N_2而将NH_2OH氧化到NO_3~-.因
Oscillopolarographic titration with potassium ferricyanide as a titrant is known as the potassium ferricyanide titration.The potassium ferricyanide solution has many advantages as a titrant: (1) Potassium ferricyanide can obtain high purity, Not hygroscopic, equivalent large, itself can be used as a reference material. (2) potassium ferricyanide aqueous solution is very stable, such as dark preservation, 0.1mol·L -1 solution concentration unchanged within five weeks its alkaline The solution is also stable at higher temperatures. (3) Potassium ferricyanide is a relatively weak oxidizing agent which has a selective oxidation behavior not found in strong oxidizing agents. It oxidizes Sn (II) without oxidation in hydrochloric acid It oxidizes S_2O_4 ~ (2-) to SO_3 ~ (2-), which can oxidize N_3H_4 to N_2 and oxidize NH_2OH to NO_3 ~