问题 选择题

在373K时,把0.5摩N2O4气体通入为5升的真空密闭容器中,立即出现棕色,反应进行到2秒时,NO2的浓度为0.02摩/升,在60秒时,体系已达平衡,此时容器内压强为开始时的1.6倍,下列说法正确的是

A.前2秒,以N2O4的浓度变化表示的平均反应速度为0.01摩/升·秒

B.在2秒时体系内压强为开始时压强的1.1倍

C.在平衡体系内含N2O40.25摩

D.平衡时, N2O4的转化率为40%

答案

答案:B

反应进行到2秒时,NO2的浓度为0.02摩/升,则此时NO2的反应速率是0.01mol/(L·s)。由于速率之比是化学计量数之比,因此N2O4的浓度变化表示的平均反应速度为0.005摩/升·秒,B不正确。2s时NO2的物质的量是0.1mol,消耗N2O4是0.05mol,所以此时体系内压强为开始时压强,B正确。设平衡时生成NO2是xmol,则消耗N2O4是X/2mol,因此有,解得x=0.6,所以选项CD都是错误的。

阅读理解

根据上文内容判断正 (T) 误 (F)。

     Mrs Jones' telephone number is 2562781 and the number of the city cinema (市影院) is 2562718.

Because the two numbers look the same, some people often make a mistake (弄错) and telephone her

when they want the cinema.

     One evening, the Jones are having supper at the table. Just then, the telephone bell rings (铃响). Mrs

Jones goes to answer the telephone. A tired (累的) man says," Excuse me, at what time does your last

movie begin?"

     "I'm sorry," says Mrs Jones," But you have the wrong (错误的) number. This is not the cinema."

     "Oh, sorry, it began twenty minutes ago (以前)? Thank you all the same. Goodbye." Says the man.

     Mrs Jones is very surprised (惊讶), so she tells her husband (丈夫) the whole thing. Her husband,

Mr Jones laughs (笑) and says:" I see. The man's wife wants to go to a movie, but he is tired. He doesn't

want to go to a movie. So he telephones the cinema. His wife hears (听见) him, but she can't hear you.

Now they stay at home this evening, and the husband is very happy and he can have a good rest (休息)

at home."

( )1. Mrs Jones' telephone number is the same as the number of the city cinema.

( )2. People often telephone Mrs Jones when they want the cinema.              

( )3. One evening when the telephone bell rings, they are having supper.       

( )4. The tired man wants to know when the last film begins.                   

( )5. The husband is happy to stay at home.                                    

单项选择题