论文部分内容阅读
1986年化学高考试题中有这样一道题:有一瓶澄清的溶液,其中可能含有 NH_4~+、K~+、Na~+、MgO~(2+)、Ba~(2+)、Al~(3+)、Fe~(3+)、SO_4~(2-)、CO_3~(2-)、NO_3~-Cl~-和 I~-。取该溶液进行如下实验:(1)用 pH 试纸试验,表明溶液呈强酸性:(2)取部分溶液,加入少量 CCl_4及数滴新制氯水,经摇荡后 CCl_4层呈紫红色;……。根据以上实验事实确定:在该溶液中肯定存在的离子是_____,肯定不存在的离子是_____,还不能确定是否存在的离子是_____。
In the 1986 chemistry exam question, there was a question: There was a clear solution, which may contain NH 4+, K+, Na+, MgO2+, Ba~2+, Al~3. +), Fe~(3+), SO_4~(2-), CO_3~(2-), NO_3~-Cl~-, and I~-. Take this solution to carry out the following experiments: (1) Test with pH test paper shows that the solution is strongly acidic: (2) Take a portion of the solution, add a small amount of CCl 4 and a few drops of fresh chlorine, and after shaking, the CCl 4 layer is purple; Based on the above experimental facts, it is determined that ions that are definitely present in the solution are _____, ions that are definitely absent are _____, and it is not yet possible to determine whether ions that exist are _____.