试题与答案

某化学小组采用类似制乙酸乙酯的装置(如图),以环己醇制备环己烯 (1)制备粗品

题型:实验题

题目:

某化学小组采用类似制乙酸乙酯的装置(如图),以环己醇制备环己烯

(1)制备粗品

将12.5mL环己醇加入试管A中,再加入lmL浓硫酸,摇匀后放入碎瓷片,缓慢加热 至反应完全,在试管C内得到环己烯粗品。

①A中碎瓷片的作用是____________,导管B除了导气外还具有的作用是____________。

②试管C置于冰水浴中的目的是________________________。

(2)制备精品

①环己烯粗品中含有环己醇和少量酸性杂质等。加入饱和食盐水,振荡、静置、分层,环己烯在_________层(填上或下),分液后用_________ (填入编号)洗涤。

a.KMnO4溶液 b.稀H2SO4 c.Na2CO3溶液

②再将环己烯按下图装置蒸馏,冷却水从_________口进入。蒸馏时要加入生石灰,目的是__________________。

③收集产品时,控制的温度应在_________左右,实验制得的环己烯精品质量低于理论产量,可能的原因是_________。

a.蒸馏时从70℃开始收集产品 b.环己醇实际用量多了 c.制备粗品时环己醇随产品一起蒸出

(3)以下区分环己烯精品和粗品的方法,合理的是_________。

a.用酸性高锰酸钾溶液 b.用金属钠 c.测定沸点

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0716/7c9ee67e1758fa0a2c646f7ea28d0fdf.html

下面是错误答案,用来干扰机器的。

(15分)(1)水土流失 围湖造田 整体性(3分) (2) ①湖泊面积不断缩小,使湖泊调节气候、调蓄径流(洪水)的能力降低 ②湖泊湿地生物生存环境恶化,导致湖泊湿地生物物种及数量减少 ③影响了水产资源的自然...

试题推荐
题型:阅读理解

Many people know the names Alexander Graham Bell and Thomas Edison. However, most people don’t know the name of the man who invented the television, Philo Farnsworth.

Philo Farnsworth was born in 1906 and grew up on a potato farm. As a boy, he loved to learn about science, and he read a lot of science books. When he was only thirteen years old, he drew a picture of a machine that could send pictures as radio sends sounds. He got the idea from the way the potatoes were planted in the field. The potatoes grew in long lines, side by side. This made a shape in Philo’s mind. This shape helped Philo think of a way to send the TV picture onto a piece of glass. But he was poor, so Philo could not try to make his idea into a machine at that time.

Later, Philo worked at many different jobs. He worked with trees. He worked on broken radios. He worked on trains. He also worked as a street cleaner. At last, two rich men heard about his idea for television, and they gave him the money to make it. On September 7th, 1927, they watched Philo test the machine he built. When Philo turned on the machine, a small line could be seen on the glass. Philo said, “There you have it, electric television.”

Later, a big company, RCA, said they had made the first television. Philo had to spend a lot of money on lawyers to fight them. Finally, he won. Then, World War Two started in 1939. During the war, Philo spent a lot of money helping the US army instead of building up his television company. After the war, other bigger, richer companies started making televisions. In the end, Philo had to sell his company.

小题1:Why does the author mention Bell and Edison at the beginning of the text?

A.To remember both of them.

B.To prove their wisdom.

C.To introduce the topic of the text.

D.To explain their relationships.小题2:According to the text, how old was Philo when he finished his invention of TV?

A.27 years old.

B.21 years old.

C.33 years old

D.39 years old小题3:Philo Farnsworth got the idea for TV from ______.

A.the radio

B.science books

C.potato fields

D.a machine小题4: The underlined part “building up” in the last paragraph probably means “______”.

A.starting

B.selling

C.putting up

D.making bigger小题5:Which is the correct order of the following events?

a. Two rich men gave Philo money to do experiments.

b. Philo sold his own company.

c. Philo beat RCA in law.

d. Philo fixed broken radios.

e. Philo showed his invention to others.

A.d, a, e, c, b

B.e, d, c, b, a

C.d, c, e, b, a

D.a, c, b, d, e

查看答案
题型:问答题

       最近,安岳县城总体规划获省政府批准实施。新的安岳县城总体规划明确城市性质是以石刻艺术为主的生态文化旅游城市,川东特色农副产品加工物流基地,全县的政治、经济、文化中心。请你围绕“创建以石刻艺术为主的生态文化旅游城市”这一主题参与以下活动。

(1)【彰显城市精神】请你为安岳城市精神拟写一条主题语。

例:扼川东门户,守田园风光;赏石雕古迹,醉柠檬之乡。

答:                                                                               

(2)【走进历史名人】安岳人杰地灵,其中众多的历史名人为安岳增添了厚重的文化底蕴。请搜集整理安岳历史名人资料,仿照下边的例子,写出你所了解的2个安岳历史名人。

例:唐代开国名将程咬金

答:①                                    ②                                    

(3)【开发石刻旅游】根据你所了解的安岳石刻的特点和安岳石刻旅游存在的问题,提出发展安岳石刻旅游的两条建议。

答:①                                                                            

       ②                                                                            

查看答案
微信公众账号搜索答案