问题 实验题

(15 分)

苯乙酸铜是合成优良催化剂、传感材料——纳米氧化铜的重要前驱体之一。下面是它的一种实验室合成路线:

制备苯乙酸的装置示意图如下(加热和夹持装置等略):

已知:苯乙酸的熔点为76.5 ℃,微溶于冷水,溶于乙醇。

回答下列问题:

(1)在250 mL三口瓶a中加入70 mL70%硫酸。配制此硫酸时,加入蒸馏水与浓硫酸的先后顺序是

                          

(2)将a中的溶液加热至100 ℃,缓缓滴加40 g苯乙腈到硫酸溶液中,然后升温至130 ℃继续反应。在装置中,仪器b的作用是                     ;仪器c的名称是              ,其作用是                                           

反应结束后加适量冷水,再分离出苯乙酸粗品。加人冷水的目的是            。下列仪器中可用于分离苯乙酸粗品的是                (填标号)。

A.分液漏斗

B.漏斗

C.烧杯

D.直形冷凝管E.玻璃棒(3)提纯粗苯乙酸的方法是             ,最终得到44 g纯品,则苯乙酸的产率是        

(4)用CuCl2    • 2H2O和NaOH溶液制备适量Cu(OH)2沉淀,并多次用蒸馏水洗涤沉淀,判断沉淀洗干净的实验操作和现象是                                            

(5)将苯乙酸加人到乙醇与水的混合溶剂中,充分溶解后,加入Cu(OH)2搅拌30min,过滤,滤液静置一段时间,析出苯乙酸铜晶体,混合溶剂中乙醇的作用是                   

答案

⑴先加水、再加入浓硫酸(1分)

⑵滴加苯乙腈(1分)球形冷凝管(1分) 回流(或使气化的反应液冷凝)(1分)

便于苯乙酸析出(2分) BCE(全选对2分)

⑶重结晶(1分)   95%( 2分)

⑷取少量洗涤液、加人稀硝酸、再加AgN03溶液、无白色浑浊出现(2分)

⑸增大苯乙酸溶解度,便于充分反应(2分)

题目分析:⑴蒸馏水与浓硫酸混合应先加水、再加入浓硫酸,防止暴沸。

⑵仪器b为分液漏斗,通过分液漏斗向三口瓶a中滴加苯乙腈;仪器c为球形冷凝管,能起到冷凝回流的作用(使气化的反应液冷凝);反应结束后加适量冷水,便于苯乙酸(微溶于冷水)结晶析出,通过过滤能从混合液中分离出苯乙酸粗品,过滤所用的仪器主要有漏斗、玻璃棒、烧杯等。

⑶将粗苯乙酸晶体重新在热水中溶解,然后再降温结晶过滤(重结晶)可得较纯净的苯乙酸晶体;根据“1~1”关系式,可计算苯乙酸的产率=

⑷在制备Cu(OH)2沉淀的同时还有可溶性NaCl生成,故判断沉淀洗干净的方法就是检验最后一次洗涤液中是否还含有Cl

⑸根据“苯乙酸微溶于冷水,溶于乙醇”,故乙醇与水的混合溶剂中的乙醇能增大苯乙酸的溶解度,便于充分反应。

单项选择题 A3型题
阅读理解

阅读理解。

     I am especially interested in eco-friendly cars. Would you please give me some help? 

                                                                                                                                         -John Lily

John Lily,

     More and more automobile companies are taking measures to create cars that do less harm to the planet.

Here are some of the top green cars this year.

Tesla Roadster

     This is an electric sports car. You can travel 220 miles before recharging the battery. The only problem?

It will cost you $ 100 000. So, until you win the lottery or happen to find a box of gold at the end of a

rainbow, let's move on to the more reasonable choices.

Aptera 2e

     This electric car is much more affordable than the Tesla Roadster, with a starting price of around $ 25000.

Its electric motor runs 100 miles per charge. Unfortunately, it is currently only available in California through

a complex booking process.

Toyota Prius

     At 51 miles per gallon in the city and 48 0n the highway, the Toyota Prius is one of the most fuel-efficient

cars in the world. With an annual CO2 rating of 1968 kilograms, this car holds the first place on MSN's list of

the Least Polluting Vehicles of 2009. It also has other eco-friendly features like a solar-powered ventilation (通

风) system. 

Honda Civic Hybrid (混合动力车)

     The Honda Civic Hybrid is competitive with the Toyota Prius when it comes to fuel efficiency. It gets 40

miles per gallon in the city and 45 on the highway. It also has the second- lowest annual CO2 figure, releasing

2160 kilograms in a year.

Honda Insight Hybrid

     With a base price of just $20 000, the Honda Insight Hybrid is the least expensive Hybrid on the market

today. Coming just after the Honda Civic and Toyota Prius in terms of pollution, this fuel-efficient vehicle gets

40 miles per gallon in the city and 43 on the highway.

     Besides all these, Toyota Camry Hybrid is also a good choice. 

                                                                                                                                                 William

1. Compared with Aptera 2e, Tesla Roadster _____.[ ]

A. costs less

B. needs more time to be recharged

C. is harder to book

D. runs much further per charge

2. Which of the following vehicles causes the least pollution to the environment? [ ]

A. Honda Civic Hybrid.

B. Toyota Prius.

C. Honda Insight Hybrid.

D. Toyota Camry Hybrid.

3. We can infer from the passage that _____. [ ]

A. as long as you have won the lottery, you can buy Tesla Roadster

B. only people in California are allowed to buy Aptera 2e

C. Honda Insight Hybrid may be the third least polluting hybrid of 2009

D. the fuel efficiency of the Aptera 2e must be the highest of all the vehicles mentioned

4. What might William be according to the passage? [ ]

A. A future car buyer.

B. A car expert giving advice to people online.

C. An eco-friendly car repairer.

D. An eco-friendly car designer.