问题 实验题

.(16分)某学生利用以下装置探究氯气与氨气之间的反应。其中A、F分别为氨气和氯气的发生装置,C为纯净干燥的氯气与氨气反应的装置。

请回答下列问题:

(1)装置F中发生反应的离子方程式为________________________________________。

(2)装置A的烧瓶中可装试剂_______________________________________________。

(3)B装置的名称是________________________________________________________;

E装置的作用__________________________________________________________。

(4)通入C装置的两根导管左边较长、右边较短,目的是_________________________。

(5)装置C内出现浓厚的白烟并在容器内壁凝结,另一生成物是空气的主要成分之一。请写出反应的化学方程式:_________________________________________________。

当有a mol氯气参加反应时,转移的电子总数为b个,则阿伏加德罗常数为(用含a、b的代数式表示)_________________。

(6)从装置C的G处逸出的尾气中可能含有黄绿色的有毒气体,如何处理?____________________________________________________________________________。

答案

(每空2分共16分)

(1)MnO2+4H++2Cl-=====△Mn2++Cl2↑+2H2O

(2)生石灰或固体氢氧化钠

(3)干燥管 除去氯气中的氯化氢

(4)使密度大的氯气与密度小的氨气较快地均匀混合

(5)3Cl2+8NH3===N2+6NH4Cl  b/2a mol-1

(6)在G连接导管直接通入盛有烧碱的烧杯中

:(1)浓盐酸和二氧化锰在加热条件下反应生成氯化锰、氯气和水,MnO2+4H++2C1- Mn2++C12↑+2H2O.

(2)利用物质溶解时放出的热量促进氨水的挥发来制取氨气,且该物质和氨气不反应,氨气是碱性气体,所以溶解的物质必须是碱性物质,A.碱石灰、C.生石灰、E.烧碱都是碱性物质,且溶解于水时放出热量,D.五氧化二磷

、B.浓硫酸虽然溶于水时放热,但是酸性物质.

故选A、C、D.

(3)氨气中混有水蒸气,氨气是碱性气体,要除去水蒸气只能用碱性物质,故选Ⅱ;制取的氯气中混有氯化氢气体和水蒸气,氯化氢极易溶于水,氯气也能溶于水,所以不能用水除去氯化氢气体;氯气和水反应生成盐酸和次氯酸,食盐水中含有氯离子,能抑制氯气的溶解,所以要想除去氯气中的氯化氢E应选Ⅰ;水蒸气常用浓硫酸除去,故D选Ⅲ.

故答案为:Ⅱ、Ⅲ、Ⅰ.

(4)氯气和氨气在常温下混合就能发生反应生成氯化铵和氮气8NH3+3C12=6NH4C1+N2;

氯化铵中含有氯离子和铵根离子,氯离子用硝酸酸化的硝酸银溶液检验;氨气用紫色石蕊试纸检验;检验方法为:将固体在烧杯中溶解,用试管取少量溶液,然后滴加少量硝酸酸化的AgNO3溶液,有白色沉淀产生,证明有C1-;用试管取少量溶液,加入浓烧碱溶液,加热,再将湿润的红色石蕊试纸放在试管口,红色石蕊试纸变蓝证明有NH4+.

故答案为:8NH3+3C12=6NH4C1+N2;将固体在烧杯中溶解,用试管取少量溶液,然后滴加少量硝酸酸化的AgNO3溶液,有白色沉淀产生,证明有C1-;用试管取少量溶液,加入浓烧碱溶液,加热,再将湿润的红色石蕊试纸放在试管口,红色石蕊试纸变蓝证明有NH4+.

(5)氯气有毒,所以不能直接排空,但氯气能和水反应生成盐酸和次氯酸,盐酸和次氯酸都能和氢氧化钠反应生成盐,所以除去氯气应选用氢氧化钠溶液吸收,方法为:将导气管与G口连接,另一端插入盛有NaOH溶液的烧杯中.

故答案为:将导气管与G口连接,另一端插入盛有NaOH溶液的烧杯中.

阅读理解

阅读理解

     A new study suggests that the more teenagers watch television,the more likely they are to develop

depression(抑郁) as young adults.But the extent to which TV may be to blame is a question that the

study leaves unanswered.

     The researchers used a national longterm survey of adolescent health to investigate the relationship

between media use and depression.They based their findings on more than 4,000 adolescents who were

not depressed when the survey began in 1995.

     As part of the survey,the young people were asked how many hours of television or videos they

watched daily.They were also asked how often they played computer games and listened to the radio.

Media use totaled an average of 5 and onehalf hours a day.More than 2 hours of that was spent

watching TV.

     7 years later,in 2002,more than 7 percent of the young people had signs of depression.The average

age at that time was 21.

Brian Primack at the University of Pittsburgh Medical School was the lead author of the new study.He

says every extra hour of television meant an 8 percent increase in the chances of developing signs of

depression.

     The researchers say they did not find any such relationship with the use of other media such as movies,

video games or radio.But the study did find that young men were more likely than young women to

develop depression given the same amount of media use.

     Doctor Primack says the study did not explore why watching TV causes depression.But one

possibility,he says,is that it may take time away from activities that could help prevent depression,like

sports and socializing.It might also interfere with sleep,he says,and that could have an influence.

     The study was just published in the Archives of General Psychiatry.

     In December,the journal Social Indicators Research published a study of activities that help lead to

happy lives.Sociologists from the University of Maryland found that people who describe themselves as

happy spend less time watching television than unhappy people.The study found that happy people are

more likely to be socially active,to read,to attend religious services and to vote.

1. According to the first paragraph,what remains unsolved in the new study?

A. Who is more likely to be influenced by TV.

B. How much teenagers are depressed by TV.

C. Whether teenagers are influenced by TV.

D. What should be done to help the teenagers.

2. More than 4,000 adolescents were chosen as the subjects of the study because they ______.

A. were free from depression

B. were keen on using the media

C. attached much importance to their health

D. could afford the time for the long-term survey

3. What can be inferred from the seventh paragraph?

A. Depression is not related to the use of other media than TV.

B. Every extra hour of media use increases the chance of depression.

C. Longer use of media other than TV doesn't increase the chance of depression.

D. The influence of movies,video games and radio on depression varies respectively.

4. In the last sentence of the eighth paragraph,"It"refers to ______.

A. depression      

B. watching TV

C. lack of activities  

D. the result of the study

5. The study done by the sociologists from the University of Maryland was mainly intended to ______.

A. tell the difference between happy and unhappy people

B. prove the relationship between TV and depression

C. stress the importance of being socially active

D. provide a happy recipe(秘方)for all people

单项选择题