题干

某溶液仅含下列离子中的几种,且所含各种离子的物质的量浓度均为0.lmol/L(忽略水的电离及离子的水解).K+  Ag+  Mg2+  Al3+   NH4+  Cl  CO32  NO3  SO42  I

用如下各步实验分析该溶液组成:

①取5mL溶液,滴少量稀氨水,发现溶液中有沉淀生成,且离子种类增加.

②用铂丝蘸取溶液,在火焰上灼烧,透过蓝色钻玻璃观察,火焰不显紫色.

③另取溶液加入过量盐酸,有无色气体生成,该无色气体遇空气变成红棕色.

④向步骤③实验所得的溶液中加入BaCl2溶液,有白色沉淀生成.

请回答下列问题:

(1)由步骤②判断,溶液中一定不含有的阳离子是____ ;步骤③中生成无色气体的化学式是____ 

(2)最终确定溶液中所含阴离子有____ 

(3)另取100mL原溶液,加入足量的NaOH溶液,充分反应后过滤,洗涤,灼烧沉淀至恒重,得到的固体化学式为____ .

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答案(点此获取答案解析)

K+,NO,Cl、I、NO3、SO42,MgO

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    There is an old English saying, "Laughter is the best medicine." One person certainly would have agreed with this is Norman Cousins.

    Norman Cousins was the editor of a magazine called Saturday Review for almost forty years. He also 1 and spoke about world peace and anti-war issues(反战议题), traveling to many different countries to share his 2.

    In the 1960s, after returning to the United States from a busy and tiring trip to Europe. Mr. Cousins got 3. He discovered he had a strange disease that caused great pain in his bones(骨头).

    In less than a week after he got back, he could not 4 it. Every move that he made was painful. He was not able to 5 at night. The doctor told Mr. Cousins that they did not know how to cure (治疗)his problem and he might never 6 the illness. Mr. Cousins, however, refused to give up hope.

    Mr. Cousins thought that the illness could be caused by 7 thoughts. He did not want to take 8 to cure himself. Instead, he felt that happy thoughts or laughter might cure his illness.

    He began to experiment on himself while still in the hospital by watching comedy shows on television. Mr. Cousins quickly found that ten minutes of 9 laughter during the day gave him two hours of pain-free sleep at night.

    Deciding that the 10 could not help him, Mr. Cousins left the hospital and checked into a hotel room where he could 11 his experiments with laughter. For eight days, Mr. Cousins 12 in the hotel room watching comedy shows on television, reading amusing books, and sleeping whenever he felt 13. Within three weeks, he felt well enough to take a vacation to Puerto Rico where he began running on the beach for 14.

    After a few months, Mr. Cousins was 15 to carry on his work. He had laughed himself back to health.