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在定性分析化学中,常采用过氧化铬法鉴定三价铬离子的存在。长期以来,国内所有分析化学教材中所叙述的分析方法是“先在过量的氢氧化钠存在下,用过氧化氢将CrO_2~-离子氧化为CrO_4~(2-)离子,然后煮沸除尽过量的过氧化氢,加HNO_3酸化试液,加戊醇或乙醚、再加1—2滴(3%)的过氧化氢,使生成过氧化铬(CrO_5):Cr_2O_7~(2-)+4H_2O_2+2H~+=CrO_5+5H_2O生成的CrO_5萃取到戊醇层,显特征蓝色,即显示有Cr~(3+)离子”。这样的分析程序,往往
In qualitative analytical chemistry, chromium peroxide is often used to identify the presence of trivalent chromium ions. For a long time, all the analytical chemistry teaching materials described in the domestic analytical method is "first in the presence of excess sodium hydroxide, hydrogen peroxide to CrO_2 ~ - ions into CrO_4 ~ (2-) ions, and then boil over the excess Hydrogen peroxide, plus HNO3 acidification test solution, add pentanol or ether, add 1-2 drops (3%) of hydrogen peroxide to produce chromium (CrO_5): Cr_2O_7 ~ (2 -) + 4H_2O_2 + 2H ~ + = CrO_5 + 5H_2O generated CrO_5 extracted to amyl alcohol layer, was characterized by blue, that is, Cr ~ (3 +) ions. Such an analysis program, often