问题 问答题

某研究性学习小组设计了一组实验来探究ⅦA元素的原子得电子能力强弱规律.下图中A、B、C是三个可供选择制取氯气的装置,D的玻璃管中①②③④依次放置蘸有NaBr溶液、淀粉碘化钾溶液、NaOH浓溶液和品红溶液的棉球,完成下列问题:

(1)写出装置B中指定仪器的名称:a______; b______

(2)该小组查阅资料显示实验室制取氯气还可采用下列原理:

2KMnO4+16HCl═2KCl+2MnCl2+5Cl2↑+8H2O

根据该原理需要选择A、B、C装置中的______装置制取氯气.

(3)反应装置的导气管与D装置的______导管(选X或Y),写出D装置中

①处棉球的离子反应方程式:______;

②处棉球的现象:______;

③处棉球的离子反应方程式:______;

(4)D装置中④的作用:______.

(5)某同学根据①②两处棉球颜色的变化得出结论:Cl、Br、I原子得电子能力依次减弱,你认为上述实验现象能证明上述结论吗?说明理由.

______.

答案

(1)a为分液漏斗,b为圆底烧瓶,故答案为:分液漏斗;圆底烧瓶;

(2)高锰酸钾与浓盐酸反应较为剧烈,无需加热即可进行,故答案为:A;

(3)检验氯气的性质时,不能先通过NaOH溶液,否则会消耗氯气,且起不到尾气吸收的作用,应从X端进气,

氯气与NaBr溶液反应生成Br2,反应的离子方程式为Cl2+2Br-=2Cl-+Br2

与碘化钾溶液反应生成I2,反应的离子方程式为Cl2+2I-=2Cl-+I2,棉球变蓝;

氯气在碱性溶液中自身发生氧化还原反应,反应的离子方程式为Cl2+2OH-=Cl-+ClO-+H2O,

故答案为:X;Cl2+2Br-=2Cl-+Br2;棉球变蓝;Cl2+2OH-=Cl-+ClO-+H2O;

(4)氯气与水反应生成HClO,具有漂白性,能使品红褪色,把品红放在最后可观察氯气是否被吸收完全,

故答案为:观察氯气是否被吸收完全(其它合理表达均可);

(5)由于不能保证氯气和溴化钠完全反应,则生成的溴单质中含有过量的氯气,则不能证明Br和I得电子能力相对强弱,

故答案为:不能,因为实验无法证明Br和I得电子能力相对强弱.(其它合理表达均可).

阅读理解

Not all memories (记忆)are sweet. Some people spend all their lives trying to forget bad experiences. Wars and traffic accidents can leave people with terrible physical and mental scars. Often they appear again in dreams.

Now American researchers think they are close to developing a pill(药丸), which will help people forget bad memories. The pill is designed to be taken immediately after a frightening experience. They hope it might reduce(减少), or possibly erase(抹去) the effect of sad memories.

In November, some scientists tested a drug(药) on people in the US and France. The drug stops the body producing chemicals(化学品) that fix memories in the brain. So far the research has suggested that only the mental effects of memories may be reduced, not that the memories are erased.

The research has caused plenty of argument. Some think it is a bad idea, while others support it.

Supporters say it could lead to pills that prevent or treat soldiers’ troubling memories after war. They say that there are many people who suffer from terrible memories.

“Some memories can destroy(破坏) people’s lives. They come back to you when you don’t want to have them in a dream. They usually come with very sad feeling.” said Roger Pitman, a scientist of psychiatry at Harvard Medical School. “This could relieve(减轻) a lot of that suffering.”

But those who are against the research say that it is very dangerous to change memories because memories give us our identity(特质). They also help us all get away from the mistakes of the past.

“All of us can think of bad events in our lives that were terrible at the time but make us who we are. I’m not sure we want to erase those memories,” said Rebecca Dresser.

小题1:The passage is mainly about __________.

A.a new medical invention

B.a new research on memories

C.a way of erasing sad memories

D.an argument about the research on the pill小题2:The drug tested on people can __________.

A.cause the brain to fix memories

B.stop people remembering their experiences

C.prevent body producing certain chemicals

D.erase the emotional effects of memories小题3:The word “scars” in Paragraph One is close in meaning to _________.

A.good stories

B.sad feelings

C.experiences

D.memories小题4:Which of the following does Rebecca Dresser agree with?

A.Some memories can destroy people’s lives.

B.People want to get away from bad memories.

C.Experiencing bad events makes us different from others.

D.The pill will reduce people’s sufferings from bad memories.

多项选择题