问题 填空题

在常温下的密闭容器中充入一定量的CH4、O2和足量Na2O2,用电火花不断引燃,待反应完全后,恢复到原温度,容器内压强几乎为0。求:

(1)容器内CH4和O2的物质的量之比应为__________。

(2)若容器中Na2O2的质量为23.4 g,则容器中O2的质量m的范围为__________。

答案

(1)2∶1 (2)m≤1.6 g

(1)容器内压强几乎为0,即无气体剩余,则所有元素以固体形式存在,根据质量守恒知,固体产物为Na2CO3和NaOH,故有关系式:6Na2O2+2CH4+O2====2Na2CO3+8NaOH。

(2)要保证气体全部被吸收,Na2O2必须过量

6Na2O2   —    O2

6              1

0.3            n(O2)

n(O2)<0.05 mol

即m(O2)<32 g·mol-1×0.05 mol="1.6" g

多项选择题 X型题
阅读理解

While football fans feel strongly angry and shocked about mistakes made by referees (裁判) because they cannot see clearly what has happened, a small German company is quietly pleased.

For Carlos Technologies, mistakes made by referees are the kind of advertising that money cannot buy. The company has developed a tiny chip(芯片) that fits inside a football and determines whether the ball has crossed the goal line, by being able to discover its exact location on the field. The world football organization, FIFA, has shown interest in the technology. It is very possible that the new technology will be used in the 2006 World Cup in Germany.

"We've been testing the technology at the main soccer stadium in Nuremberg for some time and more recently in an under-17 FIFA Cup in Peru," said Gunter Rohmer, a director of the company. "The technology has performed well, and we're pretty optimistic that it will be used at the games in Germany next year."

The chip only weighs 12 grams, and is placed in the center of the football. It sends 2,000 signals a second to a receiver network of 12 antennas(天线),placed around the field. The receivers then send information about the ball's location to a central computer, and because it works in real time, it can immediately tell the referee whether a goal has been scored. The chip even can tell when the ball crosses the line in mid-air. Oliver Braun, one of the inventors of the chip, says that feedback from German referees was generally positive. Germany sports-wear giant Adidas is also optimistic about using this kind of chip in other ball sports.

FIFA aims to test the technology later this year at another game in Japan before deciding whether or not to introduce it in all 12 stadiums in Germany for next year's World Cup.

小题1: Carlos Technologies is pleased because ________.

A.football fans are angry with referees

B.their new product can satisfy football fans

C.their new product will have a good market

D.they can sell a lot of football in the future小题2:In the first sentence in Paragraph 2,"... mistakes made by referees are the kind of advertising that money cannot buy" means ___________.

A.Carlos Technologies can't afford the high price for advertising their product

B.Mistakes in production are also a kind of advertisement

C.Carlos Technologies has already spent a lot of money on advertising their product

D.Referees' mistakes will be of great help for the sale of Carlos Technologies' new product小题3:The underlined word "feedback" probably means ___________.

A.information given back by a user

B.advice given by someone

C.supplying food to customers

D.food given back by consumers小题4:The new product has drawn attention from some _________.

A.famous people

B.referees

C.big companies

D.countries