问题 选择题

某同学按如图所示的装置进行电解实验。下列说法正确的是(  )。

A.电解过程中,铜电极上有H2产生

B.电解初期,主反应方程式为Cu+H2SO4CuSO4+H2

C.电解一定时间后,石墨电极上有铜析出

D.整个电解过程中,H的浓度不断增大

答案

BC

电解是最强有力的氧化还原手段,有些在通常条件下不能发生的反应(如本题中铜与稀硫酸)通过电解的方法可以发生反应。阳极反应:Cu-2e=Cu2,阴极反应:2H+2e=H2↑(起始),随着电解的进行,阳极产生的Cu2浓度增大,在电场的作用下向阴极移动,由于Cu2的氧化性大于H,因此Cu2也会在阴极放电生成铜,即阴极上先是H得电子放出H2,后是Cu2得电子析出Cu。因此在整个电解过程中,起始时H的浓度不断减小,随后基本保持不变。

阅读理解

China has a growing love affair with the cars.This is clear at the Beijing Asian Games Village Automobile Exchange, where more and more people come to look and increasingly to buy.

Alice Wu is an editor at a Chinese Internet publication.She takes the subway to work, but she is certain she can cut her commute time if she drives herself.Wu says it takes her three hours to get to work now.If she had a car, she says, the same trip would only take her two hours.

The Asian Games Village Automobile Exchange is the biggest car dealership in Beijing.General manager Guo Yong says the business sells more than two thousand cars each week.Guo says it is much easier for Chinese consumers to buy a car now.In the past, it would take them several years to earn enough money to buy a new car.Now, he says, many people only need to save for one year.Also, the emergence of less expensive domestic brands like Chery and BYD means more Chinese can afford cars.

For decades, most Chinese city residents got about by bicycle or public buses and trains.Now, in many areas, the number of new cars is growing faster than the road system, leaving city streets jammed with traffic.Guo Liang has wanted to buy a car for a decade, and he will be the first in his family to own one.He is not deterred by Beijing's traffic jams.Guo says if the traffic is too bad, he will use the car for leisure or holidays with his family.Another customer, Zhang Menxin, works in Beijing, but is from Xi'an, more than 900 kilometers away.Zhang says it is very difficult to get a train ticket to return home for Chinese New Year.She adds that train is not convenient.If she had her own car, she says, she could go anytime she wanted to.

World Bank transportation specialist Shomik Mendhiratta says, “Getting a car makes people feel like they have arrived to the middle class, and it's got a huge status associated with it.It's a fantastic thing to have.”

小题1:The underlined word "deterred" in the 4th paragraph probably means           .

A.encouraged

B.attracted

C.astonished

D.discouraged小题2:The reason why Zhang Menxin wants to buy a car is that          .

A.it is hard and inconvenient for her to go home in Xi'an by train.

B. she doesn't like to go to work by subway.

C.she wants to use the car for leisure or holidays with her family

D.the place where she works is far from her house小题3:The best title for the passage should be "          "

A.Cars made China a country on wheels

B.More Chinese Hitting the road in their own cars.

C.More cars sold by the Beijing Asian Games Village Automobile Exchange

D.China is developing rapidly in the past few years.小题4:According to what Shomik Mendhiratta in the last paragraph, the car is ____ for the person who owns it.

A.of little value

B.a means of transportation

C.a status symbol

D.a heavy burden

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