问题 实验题

(15分)实验室里用乙醇和浓硫酸反应生成乙烯,进而制取1,2-二溴乙烷。

(1)用下列仪器(短接口或橡皮管均已略去)完成该实验,若气体流向为从左到右,则正确的连接顺序是:

B经A(1)插入A中,D接A(2);A(3)接______接______接______接______。

(2)温度计水银球的正确位置是_______________________________。

(3)D与分液漏斗相比,其主要优点是________________________________。

(4)E装置烧杯中的冷水和反应管内液溴上的水层作用均是________________,若将装置F拆除,在E中的主要副反应为_________________________________。

(5)若要准确测定乙烯的产量,下列方案可行的是_____________________。

方案I:将E及其后面的装置拆除后,连接图28—1所示装置进行实验,反应结束后,测其实验前后的质量,由此得到乙烯产量。

方案II:将E及其后面的装置拆除后,连接图28—2所示装置进行实验,反应结束后,测得乙烯的体积,由此算得乙烯产量。

答案

(共15分)

(1)C、F、E、G(3分)                  

(2)位于三颈烧瓶的液体中央;(2分) 

(3)平衡上下气压,使液体顺利滴下;(2分)

(4)减少溴的挥发损失(2分);SO2+Br2+H2O="=" H2SO4+2HBr(3分)

(5)方案II(3分)

阅读理解

To be able to motivate oneself, or self-motivate, occurs when a person has the willingness to do something and is internally(内在地) motivated to do it.

Sometimes it’s very difficult to get ourselves moving. The natural tendency is to postpone. Life just seems to get in the way! There is a job to go to, groceries to do, television to watch—whoops! I guess we get pretty good at finding excuses to escape getting started on goals like an exercise routine or reading a new book. The fact is that we are creatures of routine and habit. So what can we do to motivate ourselves to accomplish our goals? 

Here are some tips on how to get moving:

l Decide what you want. It’s hard to motivate an aimless mind. Set a goal and decide how you are going to go about it. Then break it down into smaller sections so it’s easier to handle and less overwhelming.(势不可挡)

l Keep track of your progress. Keep a log or journal where you can measure how much you have accomplished. Looking at it can also motivate you to keep pushing ahead.

l Post motivating pictures or slogans within your sight. It is always inspiring to see pictures of people who have accomplished what you’re going for. It makes it attainable and realistic. Likewise, little slogans like “go for it” or “just do it” can give you the little support you need.    

Sometimes we forget what we set out to do and a little reminder is all we need to be revitalized (激活) and focus on the end result. If you remind yourself to go for the desired promotion, it will re-establish why you are doing what you’re doing.

l Make it a habit. Once you have accomplished your objective, e.g. becoming an early riser, keep it up so that it’s second nature to you and you don’t have to think about it anymore.

64. According to the author, some people fail to achieve their goals because ________.

A. they don’t have enough desire

B. their life is filled with routine work

C. they benefit from the force of habit

D. they naturally put off forming new habits

65. It can be inferred from the underlined sentence that ________.

A. self-motivation needs repeated self-reminding of one’s goal

B. in modern society people tend to become forgetful

C. when we forget our goal, our life becomes meaningless

D. we can achieve our goal only by focusing on the end result

66. To get moving on your goal, you can do the following EXCEPT ________.

A. keep a diary to clearly judge your distance to your goal

B. make self-improvement your second nature

C. forget your aim and revitalize yourself with slogans

D. support yourself by hanging inspiring pictures in your house

67. Which of the following is the best title for the passage?

A. Set Goals in Your Life                                          B. Get Yourself Motivated

C. Get into Good Habits                                          D. Do Not Postpone

单项选择题