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一、序言1.硫酸銨分离锶鈣的机構在定性分析中对锶鈣的分离有时濃硫酸銨溶液作为試剂。如果在含有锶鈣的溶液中加入过量的硫酸铵,硫酸锶沉淀,硫酸鈣則留在溶液中。硫酸鈣不沉淀的原因,在很多教科書中認为是因生成(NH_4)_2[Ca(SO_4)_2]絡合物,也有的教科書認为是CaSO_4的溶解度比SrSO_4大,SrSO_4在水中的溶度積为2.9×10~(-7),而CaSO_4在水中的溶度積为6.1×10~(-5),是利用分沉淀的原理,使Sr~(2+)和Ca~(2+)部分分离。生成(NH_4)_2[Ca(SO_4)_2]絡合物的解释,現在还沒有找到实驗根据,並且按照
I. Preface 1. Ammonium sulfate separation Strontium calcium mechanism In the qualitative analysis of strontium calcium separation sometimes concentrated ammonium sulfate solution as a reagent. If the solution containing strontium calcium excess ammonium sulfate, strontium sulfate precipitation, calcium sulfate is left in solution. The reason why calcium sulfate is not precipitated is believed to be due to the formation of (NH_4) _2 [Ca (SO_4) _2] complexes in many textbooks. Some textbooks also consider CaSO_4 to be more soluble than SrSO_4 and SrSO_4 in water Product is 2.9 × 10 ~ (-7), while the solubility product of CaSO_4 in water is 6.1 × 10 ~ (-5), which makes Sr 2+ and Ca 2+ Partially separated. Generation (NH_4) _2 [Ca (SO_4) _2] complex explanation, now has not found the experimental basis, and in accordance with