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用氧化还原滴定法测定锰(Ⅱ),必须除去过量的氧化剂,操作麻烦费时。Willard与Greathouse用高碘酸盐作氧化剂将锰(Ⅱ)氧化成高锰酸盐 2Mn~(2+)+5IO_4~-+3H_2O=2MnO_4~-+5IO_3~-+6H~+企图用氧化还原滴定法测定生成的高锰酸盐,但生成物碘酸盐与过量的高碘酸盐都是强氧化剂干扰高锰酸盐的滴定,虽然在pH 3条件下钼酸铵能掩蔽过量高碘酸盐,但是碘酸盐的干扰仍不能消除。J.W.H-amya与A.Townshend改用碘法,用硫代硫酸钠同时滴定生成物高锰酸盐与碘酸盐间接测得锰量。但是他是在3%或6%的硝酸介质中氧化,由于酸度大,反应速度慢,须在沸水浴中加热30min以上,为了掩蔽过量高碘酸盐。需中和硝酸后,再调pH 3,操作麻
Determination of manganese (II) by redox titration requires removal of excess oxidant, which is cumbersome and time-consuming to operate. Willard and Greathouse Oxidation of Manganese (II) to Permanganate with Periodate as Oxidant An attempt to oxidize manganese (II) to permanganate using a redox titration The resulting permanganate was assayed but both iodate and excess periodate were strong oxidants that perturb titration of permanganate, although ammonium molybdate masked excess periodate at pH 3 , But the iodate interference still can not be eliminated. J.W.H-amya and A.Townshend switched to iodine method, with sodium thiosulfate simultaneous titration of the product of permanganate and iodate indirectly measured manganese content. But he is oxidized in 3% or 6% nitric acid medium. Due to the large acidity, the reaction is slow and must be heated in a boiling water bath for more than 30 min, in order to mask excess periodate. Need to neutralize nitric acid, then adjust pH 3, operating hemp