问题 实验题

某化学兴趣小组对一包干燥的红色粉末组成进行探究,请你参与并回答有关问题。

【老师提醒】它由铜、氧化铁两种固体中的一种或两种组成。

一、【提出猜想】红色粉末可能的组成有:

①只有铜;

②只有        

③是铜、氧化铁的混合物

【资料获悉】

①铜在氯化铁溶液中发生反应:2FeCl3+Cu=2FeCl2+CuCl2

②氧化铁能被稀盐酸溶解:Fe2O3+6HCl=2FeCl3+3H2O

二、【实验探究】

(1)甲同学取少量红色粉末于试管中,滴加足量稀盐酸,震荡后观察,发现固体全部溶解。甲同学认为可以排除猜想中的①和③,而乙同学认为只能排除猜想①,你认为            (填“甲”或“乙”)的观点正确。

(2)丙同学为进一步确定红色粉末的组成,称取该粉末5g装入硬质玻璃管中,按下图在同分橱中进行试验。开始时缓缓通入CO气体,过一段时间后再加热使其充分反应。待反应完全后,停止加热,仍继续铜CO气体直至玻璃管冷却。反应前后称量相关装置和物质的总质量,其数据如下表:

三、【讨论交流】

(1)在装置A中先通入CO气体的作用是                          

(2)应该选择          组的实验数据计算确定红色粉末的组成。最终计算结果表明:该红色粉末的组成是猜想中的第          组(填序号)

(3)写出A装置中发生的化学方程式及现象                                    。

(4)为了防止溶液倒吸,本实验停止加热前是否需要先断开A和B的连接?          (填“需要”或“不需要”),理由是                                              

四、【反思评价】丁同学指出:从环保角度,上图装置有严重不足之处。你认为应该如何改进?                                                                              

答案

一、【提出猜想】Fe2O3  

二、【实验探究】乙  

三、【讨论交流】

(1)排尽玻璃管中的空气,防止加热时发生爆炸。

(2)Ⅰ;③    

(3 )Fe2O3+ 3CO2Fe+3CO2,红色粉末部分变成黑色  

(4 )不需要;因为停止加热后仍需通入CO气体,A 中管内气压不会减小,B 中溶液不会倒吸入A 中。  

四、【反思评价】在B 装置右侧导管末端放一只燃着的酒精灯(或扎紧一只瘪气球)

阅读理解

阅读理解

       Share Your Ideas and Experiences!

       Hi, my name is Christina Baum. I'm a fourteen-year-old German students. I'm writing to tell you

about an experiment we are doing at school with our Science teacher. At the beginning of this school

year, Frau Keller showed us films and we read articles about problems in the environment. One day she

said: "I want to know what you think. Please don't tell me what we should do or must do. Tell me what

each of you will do to protect the environment."

       She asked us to choose a topic, make a weekly plan and tell the class about it. Then we had to do

things to be "green" and write a report about our achievements. Some students said that they thought it

was impossible for a single person to contribute to the protection of the environment. Someone else said

that scientists should work harder to find new ways to produce energy.

       Frau Keller said that it is everyone's job to care for the health of the planet. After the first week everybody in class was excited about the project and wanted to continue to improve their results. Someone

suggested telling the other classes in the school. Now all 768 students at Hermann Stein School are

working on the project. At the end of the year, our class will write a report about what we have achieved.

       Next week I'll think about how not to waste water or make it dirty. I'm planning to try and use less

water every day, and also not use so much of the things that make it dirty. Every time I turn on the tap I

must think about how much water and soap I use.

       To use less water, this is what I'll do:

       —take a shower instead of baths;

       —turn off the tap while brushing my teeth;

       —use less washing-up liquid when washing dishes.

       If you want to know more or join us, please write an email to the following address: k.keller@

hermannsteinschool.edu mailto:k.keller@hermannsteinschool.edu

1. Why is Christina working on the project?

A. Because the Science teacher asked them to.

B. Because she wanted to be "green".

C. Because it will help to find new ways to produce energy.

D. Because she uses too much water at home.

2. What does the word "green" mean in Paragraph 2?

A. To make films on the environment.

B. To make scientists work harder.

C. To write articles on the environment.

D. To be kind to the environment.

3. What do the students have to do for the experiment?

A. Do things that use water and write a report.

B. Do things that are bad for the environment and write a report.

C. Do things that help to protect the environment and write a report.

D. Do things that are exciting and write a report.

4. What will Christina do to stop wasting water?

A. Reduce the number of baths and showers she takes.

B. Take showers instead of baths.

C. Brush her teeth in the shower.

D. Reduce the number of taps in her house.

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