问题 实验题

S2C12是一种金黄色易挥发的液体,常用作橡胶硫化剂。某化学兴趣小组拟设计实验制备少量的S2C12,査阅资料知S2Cl2在水中易发生歧化反应(一部分硫元素化合价升高,另一部分化合价降低)。加热条件下硫单质和干燥、纯净的Cl2反应即可生成S2C12,反应的化学方程式为:2S+Cl2S2Cl2

反应涉及的几种物质的熔沸点如下:

物质SS2Cl2
沸点/℃445138
熔点/℃113-76
该小组设计的制备装置如下图(夹持仪器已略去)

回答下列问题:

(1)连接好实验装置后的第一步实验操作是______。

(2)实验中需要加热的仪器是                (填写字母)

(3)装置B、C中的试剂分别是            

(4)装置D中仪器a的作用是                   

(5)反应结束后从锥形瓶内混合物中分离出产品的方法是____________。

(6)若实验过程中缺少C装置,发现产品浑浊不清,请用化学方程式表示其原因____________。

(7)实验完毕,小组中的一位同学把剩余浓盐酸倒入E烧杯中,发现有黄绿色剌激性气体产生。用离子方程式表示产生该现象的原因____________。

答案

(1)检查装置的气密性

(2)AD

(3)饱和食盐水   浓硫酸

(4)冷凝回流、导气

(5)蒸馏

(6)2S2Cl2+H2O=4HCl↑+2S↓+SO2

(7)ClO-+Cl-+2H+=Cl2↑ +H2O

(1)实验前要检查气密性;

(2)制备氯气要加热,加热条件下硫单质与干燥、纯净的氯气反应就可以生成S2Cl2,即选AD;

(3)除去氯气中HCl和H2O,应选择饱和食盐水、浓硫酸;

(4)知道冷凝管的作用,冷凝回流、导气;

(5)根据S2Cl2的性质,应采用蒸馏;

(5)缺少C装置,H2O会进入D装置,S2Cl2会发生氧化还原反应;

(7)多余的氯气用NaOH溶液吸收;

阅读理解

The clock struck eleven at night. The whole house was quiet. Everyone was in bed except me. Under the strong light, I looked sadly before a huge pile of troublesome stuff they call “books”.

I was going to have my examination the next day. "When can I go to bed?" I asked myself. I didn’t answer, in fact I dared not.

The clock struck 12. "Oh, dear!" I cried, "ten more books to read before I can go to bed!” We pupils are the most wretched creatures in the world. Dad does not agree with me on this. He did not have to study so hard when he was a boy ."

The clock struck one. I was quite hopeless now. I forgot all I had learned. I was too tired to go on. I did the only thing I could. I prayed, “Oh, God, Please help me pass the exam tomorrow. I do promise to work hard afterwards, Amen.”  My eyes were heavy, so heavy that I could hardly open them. A few minutes later, with my head on the desk, I fell asleep.

小题1:When the author was going over his lessons, all the others in the house were_____ .

A.asleep

B.working in bed

C.outside

D.quietly laughing at him小题2:Reviewing his lessons didn’t help him because ________.

A.it was too late at night

B.he was very tired

C.his eyes lids were so heavy that he couldn’t keep them open

D.he hadn’t studied hard before the examination小题3:What do you suppose happened to the author?

A.He went to a church to pray again

B.He passed the exam by luck

C.He failed in the exam

D.He was punished by his teacher小题4:The best title for the passage would be __________ .

A.The Night Before the Examination

B.Working Far into the Night

C.A Slow Student

D.Going Over My Lessons

单项选择题