已知A是盐类物质（正盐），从A的水溶液出发有下图所示的一系列变_爱下问搜题

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问题填空题

已知A是盐类物质（正盐），从A的水溶液出发有下图所示的一系列变化：

试回答：

（1）物质的化学式：A______，C______，D______

（2）写出A→D的离子方程式______

（3）写出E→F的离子方程式______

（4）鉴定物质F的方法______．

答案

（1）由C+氨水→A，D+C的溶液→A，知D为NH₃，则A为铵盐，由A可跟酸反应，又可与碱反应且A为正盐且为弱酸弱碱盐，A与浓硫酸反应生成B是（NH₄）₂SO₄，推知F为K₂SO₄，E为K₂SO₃，C为SO₂，即A为（NH₄）₂SO₃，B为（NH₄）₂SO₄，C为SO₂，D为NH₃，E为K₂SO₃，F为K₂SO₄，故答案为：（NH₄）₂SO₃；SO₂；NH₃；

（2）A→D为（NH₄）₂SO₃ 和KOH的反应，反应的离子方程式为NH₄⁺+OH^-

△

.

NH₃↑+H₂O，

故答案为：NH₄⁺+OH^-

△

.

NH₃↑+H₂O；

（3）SO₃^2-具有还原性，与具有氧化性的Br₂发生氧化还原反应生成SO₄^2-和Br^-，

反应的离子方程式为SO₃^2-+Br₂+H₂O=SO₄^2-+2Br^-+2H⁺，

故答案为：SO₃^2-+Br₂+H₂O=SO₄^2-+2Br^-+2H⁺；

（4）可分别检验K⁺和SO₄^2-，可用焰色反应鉴定K⁺，隔蓝色钴玻璃，火焰呈紫色，用BaCl₂检验SO₄^2-，具体做法为通过焰色反应鉴定K⁺（隔蓝色钴玻璃，火焰呈紫色）；取少量F的溶液加入BaCl₂和盐酸的溶液，若产生白色沉淀，证明SO₄^2-的存在，

故答案为：通过焰色反应鉴定K⁺（隔蓝色钴玻璃，火焰呈紫色）；取少量F的溶液加入BaCl₂和盐酸的溶液，若产生白色沉淀，证明SO₄^2-的存在．

阅读理解

阅读理解。

I am a man who has been egoistic (自我为中心的) and I have had a lack of respect for myself

and others around me. I participated in(参加) various transformation workshops, however, it made

no difference. I remained stuck in my life. As a result, I became separated from my family and reached

rock bottom in my life. Having reached there, I resisted transforming myself.

After some time, I thought to myself, start believing in yourself and it will make a difference in your life. I first started loving myself and then all those around me. I started respecting myself and then others around me. My selfworth increased.

Sangeeta is my workmate. She's transparent, honest and respectful. She's very poor and has a large

family to support. In addition, her husband doesn't hold a regular job. In short, she's struggling in life.

On a cold winter morning, when she came to work, I found her shaking. I asked whether she had a

pullover (毛线套衫). She didn't reply. I_had_my_answer. The next day when she came to work

again, I gave her the money to buy a pullover for herself. The expression of thankfulness in her eyes was

something that will remain with me for a long time.

A few weeks ago, she was ill and didn't come to work. Instead, she sent her friend to do her work.

The moment I realized Sangeeta was sick, I gave her friend the money to buy medicines for her treatment. It took Sangeeta some time to recover from her illness. The first thing I cared about was whether she needed any more help of any kind. And she said, "Sir, you've done enough for me. I'm grateful to you."

That was the moment when I realized that I'm walking my path. Sometimes, I still fall down, but I get

up and start walking again even though I may have hurt myself in the process.

1. According to the passage, attending transformation workshops ________.

A. made the author closer to his family

B. changed the author's attitude

C. had little effect on the author

D. helped the author get along well with others

2. What did the author mean by saying "I had my answer" in Paragraph 4?

A. He knew Sangeeta had no pullover.

B. He knew Sangeeta was too proud to admit her poverty.

C. He knew Sangeeta was in danger at that time.

D. He had the chance to change Sangeeta's attitude towards him.

3. When Sangeeta was ill, the author ________.

A. gave her financial help

B. helped Sangeeta do her work

C. bought her medicines for treatment

D. met with refusal when offering help

4. The passage is mainly about ________.

A. an unforgettable experience

B. changes which happen to the author

C. a woman who changed the author's life

D. the relationship between Sangeeta and the author

问答题

Custom has not commonly been regarded as a subject of any great moment.

It is the inner working of own brains that we feel to be uniquely worthy of investigation but, custom, we have a way of thinking, is behavior at its most commonplace. As a matter of fact, it is other way around. (46) Traditional custom, taken the world over, is a mass of detailed behavior more astonishing than what any one person can ever evolve in individual actions, no matter how unusual and abnormal. Yet that is a rather trivial aspect of the matter. The fact of fist-rate importance is the predominant role that custom plays in experience and in belief, and the very great varieties it may manifest.

No man ever looks at the world with primitive and unchanged eyes. He sees it edited by a definite set of customs and institutions and ways of thinking. (47) Even in his philosophical probing(探测术) he cannot go behind these stereotypes; his very concepts of the true and the false will still have reference to his particular traditional customs. John Dewey has said in all seriousness that the part played by custom in shaping the behavior of the individual, as against any way in which we can affect traditional Custom, is as the proportion of the total vocabulary of his mother tongue against those words of his own baby talk that are taken up into the vernacular(本国的)of his family. (48) When one seriously studies the social orders that have the opportunity to develop autonomously, the figure becomes no more than an exact and matter-of-fact observation.

(49) The life history of the individual is first and foremost an accommodation to the patterns and standards traditionally handed down in his community. From the moment of his birth, the customs into which he is born shape his experience and behavior. By the time he can talk, he is little creature of his culture, and by the time he is grown and able to take part in its activities, its habits are his habits, its beliefs his beliefs, its impossibilities his impossibilities. (50) Every child that is born into his group will share them with him and no child born into one on the opposite side of the globe can ever achieve the thousandth part. There is no social problem which is more responsible for us to understand than this of the role of custom. Until we are intelligent as to its laws and varieties, the main complicating facts of human life must remain unintelligible.

(48) When one seriously studies the social orders that have the opportunity to develop autonomously, the figure becomes no more than an exact and matter-of-fact observation.