问题 实验题

(7分)小明在查阅资料时得知CO2在高温时能与木炭反应生成CO ,他决定对该反应进行探究。

【提出问题】CO2与木炭在高温条件下反应是否生成CO?

【实验探究】小明设计了下图的实验方案,并进行实验。

小题1:A中用石灰石与稀盐酸反应的化学方程式为___________________。

小题2:检查装置A气密性的方法是__________________________________________

小题3:B中装有饱和碳酸氢钠溶液,其作用是除去CO2气体中混有的少量HCl气体。C中装有浓硫酸,其作用是__________________

小题4:E中氢氧化钠溶液的作用是__________________。

【实验结论】经检验F处的气体为CO。结论:CO2在高温条件下与木炭反应生成了CO。

【实验反思】

有同学对A装置作如下改进:在锥形瓶中放入一小试管,将长颈漏斗下端插入小试管中,改进后的优点是_________________。

【实验拓展】

撤去B,按A→C→D→E顺序连接。然后A中用二氧化锰和过氧化氢溶液混合生成O2,反应的化学方程式为_________________。此时要检验该实验条件下D中木炭所发生反应的所有生成物,除在F处点燃并检验生成物外,还需要补充和完善的实验是________________。

答案

【实验探究】

小题1:CaCO3+2HCl=CaCl2+H2O+CO2↑  

小题2:把导管的一端浸没在水里,双手紧贴容器外壁,若导管口有气泡冒出,装置不漏气

小题3:干燥CO2     

小题4:吸收CO2    

【实验反思】可通过控制加酸的量,控制产生气体的快慢;同时起到液封的作用。

【实验拓展】

2H2O2 2H2O+O2

在D、E之间增加盛有澄清石灰水的洗气瓶来检验CO2气体

浓硫酸有吸水性可以干燥CO2,E中氢氧化钠溶液的作用是吸收反应剩余的二氧化碳的,在锥形瓶中放入一小试管,将长颈漏斗下端插入小试管中,这样盐酸就不能一下都与大理石接触,从而可以控制加酸的量,来控制产生气体的快慢;同时也起到了液封的作用。可以用澄清石灰水的洗气瓶来检验CO2气体。

填空题
阅读理解

Ten years ago I used to be very fit. I rode a bike to work and I got a lot of exercise at weekends. I used to play tennis a lot and go for long walks. In those days I didn’t earn very much. I had a job in an office. It wasn’t a very good job but I had a lot of time to do the things I enjoyed doing.

Then, about eight years ago, I got a much better job. The pay was better, but the hours were a lot longer. I bought a car and drove to work every day. I began to take people out to lunch. And I began to put on weight, too. I stopped playing tennis and going for long walks at weekends because I just didn’t have any time for things like that any more.

There’s a lot of stress in my job. Perhaps that’s why I started drinking more than I used to. For example, I used to have only half a glass of whisky when I got home, but then I started filling my glass to the top, and instead of having one glass, I would have several. I started smoking a lot, too. I never used to smoke at all.

Two months ago I had a heart attack. At first I just couldn’t believe it. Luckily it wasn’t very serious. The doctor advised me to stop smoking and to eat less. He also advised me to work less and get more exercise. But I just haven’t any time! My job takes everything out of me!

Sometimes I wonder if I should get another job. Perhaps I could do something as I used to. But if I do that, I won’t earn as much. I have a family to support. I have to think of them, too. I just don’t know what I should do. What do you think?

小题1:Compared with ten years ago, what is worse for the author now?

A.His job.

B.His pay.

C.His means of transport.

D.His health.小题2:According to the passage, when the author got the better job, which of the following is NOT true?

A.He got higher pay.

B.His working hours weren’t long.

C.He found it very stressful.

D.He had little free time at weekends.小题3:After the author had a heart attack, the doctor advised him ____________.

A.not to work any longer

B.to take a long vacation abroad

C.to stop smoking and take exercise

D.not to eat out any more小题4:What can we learn about the author?

A.The author is not sure what he should do now.

B.The author has taken the doctor’s advice already.

C.The author has got another new job.

D.The author feels much better now.