问题 填空题

根据硫酸及其盐的性质回答下列问题。

(1)将适量的蔗糖放入一烧杯中,再加入浓硫酸,观察到蔗糖变黑,体积膨胀,并产生刺激性气味的气体。生成的黑色物质是__________(填化学式);刺激性气味的气体主要成分是_________(填化学式);该实验表明浓硫酸具有           性、          性。  

(2) “绿色化学”要求综合考虑经济、技术、环保等方面来设计化学反应路线。若以铜为原料制取硫酸铜,请你设计符合“绿色化学”思想的反应路线(用化学方程式表示)。

                                                              

答案

(1)C ;SO2 ; 脱水性、强氧化性   

(2)2Cu + O22CuO 、CuO +H2SO4=CuSO4 +H2O

(1)浓硫酸具有脱水性,能使蔗糖炭化,生成C。浓硫酸还具有氧化性,能和碳反应生成CO2、SO2和水,SO2具有刺激下气味。

(2)根据绿色化学的思想可知,要制取硫酸铜,应该先让铜生成氧化铜,然后再与稀硫酸反应即可,方程式为2Cu + O22CuO 、CuO +H2SO4=CuSO4 +H2O。

判断题
阅读理解

In business, there’s a speed difference: It’s the difference between how important a firm’s leaders say speed is to their competitive(竞争的) strategy(策略) and how fast the company actually moves.The difference is important regardless of industry and company size. Companies fearful of losing their competitive advantage spend much time and money looking for ways to pick up the speed.

In our study of 343 businesses, the companies that chose to go, go, go to try to gain an edge ended up with lower sales and operating incomes than those that paused at key moments to make sure they were on the right track.What's more, the firms that “slowed down to speed up” improved their top and bottom lines, averaging 40% higher sales and 52% higher operating incomes over a three-year period.

How did they disobey the laws of business physics, taking more time than competitors yet performing better? They thought differently about what “slower” and “faster” mean.Firms sometimes fail to understand the difference between operational speed (moving quickly) and strategic speed (reducing the time it takes to deliver value).Simply increasing the speed of production, for example, may be one way to try to reduce the speed difference.But that often leads to reduced value over time, in the form of lower-quality products and services.

In our study, higher-performing companies with strategic speed always made changes when necessary. They became more open to ideas and discussion.They encouraged new ways of thinking.And they allowed time to look back and learn.By contrast (相比而言), performance suffered at firms that moved fast all the time, paid too much attention to improving efficiency, stuck to tested methods, didn't develop team spirit among their employees, and had little time thinking

about changes.

Strategic speed serves as a kind of leadership.Teams that regularly take time to get things right, rather than plough ahead full bore, are more successful in meeting their business goals.That kind of strategy must come from the top.

小题1:What does the underlined part “gain an edge” in Paragraph 2 mean?

A.Increase the speed.    

B.Reach the limit.

C.Get an advantage.

D.Set a goal.小题2:The underlined part “the laws of business physics” in Paragraph 3 means ________.

A.spending more time and performing worse

B.spending more time and performing better

C.spending less time and performing worse

D.spending less time and performing better小题3:What can we learn from the text?

A.How fast a firm moves depends on how big it is.

B.How competitive a firm is depends on what it produces.

C.Firms guided by strategic speed take time to make necessary changes.

D.Firms guided by operational speed take time to develop necessary team spirit.小题4:Which could be the best title for the text?

A.Improve quality? Serve better.

B.Deliver value? Plough ahead.

C.Reduce time? Move faster.

D.Need speed? Slow down.