摘要
高锰酸钾在不同的环境中被还原的产物不同,这是无机化学中的典型例子.但为什么环境不同 KMnO_4的还原产物就不同,现行的教科书及文献未见报道。笔者通过作出锰在不同环境中的自由能一氧化态图,清晰,直观地解释了这一现象.从自由能一氧化态图还可看出,MnO_4^-在碱性环境比在中性,酸性中的自由能值低,表明 MnO_4^-在碱性环境比在中性、酸性环境中稳定.这与不同环境中 MnO_4^-的氧化还原稳定性结果一致.这正是KMnO_4通常在碱性界质中制备而在酸性环境中作强氧化剂使用的原因.
There are different reduced products of potassium permanganate in different medium,which is a special example in inorganic chemistry.But why?The reason is not repoted now .In term of drawing free energy-oxidation state curve,it can be explained clear.From the figure of free energy-oxidation state of manganese,it can be seen that free energy of potassium permanganate in strongly alkaline medium is less than in neutral;Lalkaline and acidic medium.So potassium permanganate is the most stable in strongly alkaline.It is the same result that is obtained from the redox stability of potassium permanganate.For that reason,potassium permanganate usually be prepared in strongly alkaline medium and used as strongly oxidant in acidic,medium.
出处
《云南师范大学学报（自然科学版）》
1991年第1期76-80,共5页
Journal of Yunnan Normal University:Natural Sciences Edition
关键词
锰
还原
高锰酸钾
产物
potassium permanganate
free energy-oxidation state figure
prepared in alkaline and used in aeidicmedium
