问题 实验题

请分析回答某同学在探究浓硫酸、稀硫酸、浓硝酸、稀硝酸分别与铜反应的实验中发现的有关问题。

Ⅰ.探究上述四种酸的氧化性相对强弱及其与铜反应的还原产物的性质

(1)分别向盛有等量铜片的四支试管中加入等体积的浓硫酸、稀硫酸、浓硝酸、稀硝酸,实验结果记录如下表:

 实验结果
a浓硫酸加热后发生反应,产生无色刺激性气体
b稀硫酸加热也不发生反应
c浓硝酸不加热即发生反应,产生红棕色气体
d稀硝酸微热发生反应,产生无色气体
 

①由上表中实验结果,四种酸的氧化性由强到弱的顺序是 。 

②由上表可知,铜与稀硫酸在加热条件下不反应,但若同时通入O2,铜片能逐渐溶解,溶液变为蓝色。写出该反应的化学方程式:                    。 

(2)先将铜与浓硫酸反应产生的气体X持续通入如图所示装置中,一段时间后再将铜与浓硝酸产生的气体Y也持续通入该装置中,则整个过程中可观察到的现象包括   (填字母)。 

A.通入X气体后产生白色沉淀

B.通入X气体后溶液无明显现象

C.通入Y气体后产生沉淀

D.通入Y气体后沉淀溶解

E.通入Y气体后溶液中无明显现象

由此可得到的结论是   (填字母)。 

A.硝酸的酸性比硫酸强

B.H2SO3的酸性比盐酸强

C.HNO3能氧化H2SO3(或SO2)

D.BaSO4既不溶于水也不溶于HNO3溶液

Ⅱ.如图是某同学探究铜与稀硝酸反应的还原产物的实验装置图,请回答下列问题:

(1)写出铜与稀硝酸反应的离子方程式:           。 

(2)已知装置气密性良好,请简述利用该装置证明铜与稀硝酸反应生成的气体产物是NO的操作过程:                                          

答案

Ⅰ.(1)①浓硝酸>稀硝酸>浓硫酸>稀硫酸

②2Cu+O2+2H2SO42CuSO4+2H2O

(2)BC CD

Ⅱ.(1)3Cu+8H++23Cu2++2NO↑+4H2O

(2)反应停止后打开b,如果看到无色气体变为红棕色,证明生成的气体是NO

根据反应条件“不加热即可发生反应”“微热发生反应”“加热后发生反应”“加热也不发生反应”可以判断氧化性由强到弱的顺序为浓硝酸>稀硝酸>浓硫酸>稀硫酸。铜、稀硫酸与O2反应的化学方程式为2Cu+O2+2H2SO42CuSO4+2H2O。铜与浓硫酸反应产生的气体X为SO2,通入BaCl2溶液中不反应,但再通入铜与浓硝酸产生的气体Y(NO2)以后,SO2被氧化为H2SO4,与BaCl2生成BaSO4沉淀。铜与稀硝酸反应产生的NO为无色气体,在U形管右上端聚集,反应一段时间停止后,打开b,如果看到无色气体变为红棕色,则证明生成的气体是NO。

阅读理解

阅读理解。

    Steven Jobs, the designer (设计者) of Apple Computer, was not clever when he was in school. At that

time, he was not a good student and he always made troubles with his schoolmates. When he went into

college, he didn't change a lot. Then he dropped out (退学). But he was full of new ideas.   

    After he left college, Steven Jobs worked as a video game designer. He worked there for only several

months and then he went to India. He hoped that the trip would give him some new ideas and give him a

change in life.   

    Steven Jobs lived on a farm in California for a year after he returned from India.   

    In 1975, he began to make a new type of computer. He designed the Apple Computer with his friend in

his garage (汽车库). He chose the name "Apple" just because it could help him to remember a happy summer

he once spent in an apple tree garden.   

    His Apple Computer was such a great success that Steven Jobs soon became famous all over the world.

1. Steven Jobs was not a good student in school because he ________.

A. never did his lessons   

B. was full of new ideas   

C. always made troubles with his schoolmates   

D. dropped out

2. What's Steven's first job after he left college?

A. Computer programmer

B. Video game designer

C. Teacher

D. Factory worker

3. Steven Jobs designed his new computer ________.

A. in India

B. in the USA

C. in an apple tree garden

D. by himself

4. Steven Jobs was famous for his ________ all over the world.

A. new ideas

B. apple

C. video games

D. Apple Computer

5. From this passage we know ________.

A. Steven Jobs liked trying new things and making his new ideas become true

B. Steven Jobs liked travelling in India and California

C. Steven Jobs didn't finish his studies in the college because he hated his schoolmates

D. Steven Jobs could only design video games

单项选择题 A型题