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判断一个离子反应方程式是否正确,应注意考虑十种因素。 一,要考虑操作程序 相同的反应物,当反应时若操作程序不同,其离子反应方程式是不尽相同的。例如将少量碳酸氢钙溶液滴入烧碱溶液中,其离子方程式为:Ca~(2+)+2HCO_(3~-)+2OH-=CaCO_3↓+CO_3~(2-)+2H_2O;而将少量烧碱溶液滴入碳酸氢钙溶液中,其离子方程式为:Ca~(2+)+HCO_(3-)+OH-=CaCO_3↓+H_2O。
To determine whether an ion reaction equation is correct, ten factors should be considered. First, we must consider the same reactants in the operation procedure. When the reaction procedure is different, the ion reaction equations are not the same. For example, a small amount of calcium bicarbonate solution is dropped into the caustic soda solution, and its ion equation is: Ca 2+ + 2 HCO 3 - - + 2 OH - = CaCO 3 ↓ + CO 3 - 2 - + 2H 2 O; The caustic soda solution was added dropwise into the calcium bicarbonate solution. The ion equation was: Ca 2+ +HCO 3 -+OH-=CaCO 3 ↓+H 2 O.