问题 实验题

某研究小组为探究SO2和Fe(NO3)3溶液的反应的实质。设计了如下图所示装置进行实验. 

已知:1.0 mol/L的Fe(NO3)3溶液的pH=1。

请回答:

(1)装置A中用于添加浓硫酸的仪器名称为                  

(2)实验前鼓入N2的目的是                                

(3)装置B中产生了白色沉淀,其成分是________,说明SO2具有________性。

(4)分析B中产生白色沉淀的原因。

观点1:SO2与Fe3反应;

观点2:在酸性条件下SO2与NO3-反应;

①若观点1正确,除产生沉淀外,还应观察到的现象是                 

②按观点2,装置B中反应的离子方程式是                              

③有人认为,如将装置B中的Fe(NO3)3溶液替换为等体积的下列溶液,在相同条件下进行实验,也可验证观点2是否正确。此时应选择的最佳试剂是(填序号)     

A.1 mol/L稀硝酸

B.1.5 mol/L Fe(NO3)2溶液

C.6.0 mol/L NaNO3溶液和0.2 mol/L盐酸等体积混合的溶液

D.3.0 mol/L NaNO3溶液和0.1mol/L硫酸等体积混合的溶液

答案

(1)分液漏斗(2分)

(2)排净装置中的空气,防止溶液中SO2被空气中的O2氧化而干扰实验(2分)

(3)BaSO4(1分);还原(1分)

(4)①静置一段时间后,溶液由棕黄色变为浅绿色(2分)

②3SO2+2NO3-+3Ba2+2H2O=3BaSO4↓+2NO+4H

或3SO2+2NO3-+2H2O=3SO42-+2NO+4H;Ba2+SO42- = BaSO4↓(2分)

 C(2分)

题目分析:(2)反应前要充入N2,排除装置A中的空气,反应对实验的干扰。

(3)硝酸具有氧化性,白色沉淀为BaSO4,说明SO2具有还原性。

(4)经过分析,各个观点,得出观点1是SO2和Fe3+、酸性条件下NO3都反应。

①Fe3+把SO2氧化,离子方程式是SO2+2Fe3++Ba2++2H2O=BaSO4↓+2Fe2++4H+

②Fe(NO3)3中有Fe3+,a错;NO3-在酸性条件下有氧化性,b错。故选c。

SO2制备 Fe3+、NO3-的氧化性。2制备 Fe3+、NO3-的氧化性。

选择题
阅读理解

阅读理解

                                                        My Best Enemy

     Once again, I was in a new school.So was a girl in my class named Lisa.That's where the similarity

ended.

     I was tall and she was small.My thick black hair had been recently cut short into an untidy style.Her

natural blonde hair flowed to her waist and looked great.I was 12 and one of the oldest in the class while

she was 11 and the youngest.I was awkward and shy.She wasn't.I couldn't stand  her, considering her my enemy.But she liked me and wanted to be friends with me.

      One day, she invited me over and I said yes-I was too shocked to answer any other way.My family

had moved six times in six years, and I had never managed to develop any friendships.But this girl who

wore the latest fashions wanted me to go home with her after school.

     She lived in a fun part of town that had two pizza places, an all night bookstore, a movie theater and a

park.As we walked from the school bus stop through her neighborhood, I tried to guess which house

might be hers.Was it the white one with the perfect lawn or the threestory house with a front porch?I got

very surprised when she led me into an old apartment building.She lived on the fourth floor in a tworoom

place with her mother, her stepfather, her two brothers and her sister.

     When we got into the room she shared with her sister, she took out a big case of Barbies, which was

my next surprise.I had never played with them.We sat on the floor, laughing as we made up crazy stories

about the Barbies.We found out that we both wanted to be writers when we were older and both had

wild imaginations.We had a great time that afternoon.

     Lisa was loved by the whole neighborhood.The bookstore owners lent her fashion magazines; the

movie theater gave her free tickets...Soon I was included in her magic world.We slept over at each

other's house and spent every free moment together.

      Lisa, my first real friend since childhood, helped me get through the rough years of early adolescence (青春期) and taught me an amazing and very surprising thing about making friends:your worst enemy can

turn out to be your best friend.

1. The writer and Lisa were similar in the way that________.

A. they were both new students

B. they had the same hairstyle

C. they were both tall

D. they were of the same age

2. One day Lisa invited the writer________.

A. to go to the movie  

B. to go to her home

C. to go to walk in a park  

D. to go to a pizza place

3. In the passage the writer described Lisa as a girl who was________.

A. awkward and shy  

B. rich and happy

C. quiet and lonely  

D. friendly and lovely

4. Which of the following did the writer learn from Lisa?

A. How to make up stories.  

B. How to deal with enemies.

C. How to make friends.  

D. How to live a better life.