问题 选择题

mA(s)+nB(g)pC(g)的可逆反应,在室温条件下φ(B)与压强(p)的关系如图4所示,则下列有关叙述正确的是(    )

图4

A.m+n<p

B.n>p

C.X点时混合物的正反应速率大于逆反应速率

D.X点比Y点混合物的反应速率慢

答案

CD

由图示可看出,随p增大,φ(B)也增长,所以,p增大时,平衡向左移动,所以n<p(注意物质A是固体,所以在此不应涉及m),选项A、B均不正确。

在曲线上,当p一定时,φ(B)也一定,所以曲线上每一点均表示达平衡状态,而曲线外各点均不是平衡状态。在曲线上方的任一点(如X点)φ(B)比平衡状态时大,则在达到平衡状态的过程中,必须使φ(B)减小,则必须是正反应速率大于逆反应速率。

由于Y点的压强比X点的压强大,所以Y点比X点混合物的反应速率大。

阅读理解

The train was already half an hour late. I had to arrive in Vienna at 7:15 in time to catch the 7:20 train to Paris, but there was no hope of that now. I told my problem to the conductor (列车员). He advised me to get off two stops before Vienna Station and take a taxi. When the time came, he even helped with my bag. He wished me good luck as I jumped off. A few minutes later I was racing towards the center of the city in a taxi. It was almost 7:25 when we stopped outside the station. I paid the driver quickly, picked up my bag and hurried inside. “Paris train?” was all I had time to say to the official I saw. You can see how I felt when he pointed to a train that was just moving out of the station.

小题1:The writer couldn’t arrive in Paris in time because       .

A.he didn’t pay the driver

B.he took the wrong train

C.the train was late

D.the conductor advised him to get off early小题2:The conductor advised the writer to get off before Vienna and take a taxi       .

A.as soon as the train stopped

B.after he heard the writer’s explanation

C.after he was passing the writer

D.when the train arrived in Vienna at 7:15小题3:Which of the following did the conductor do to help the writer?

A.The conductor advised him to get off two stops before Vienna.

B.The conductor took him to the center of the city in a taxi.

C.The conductor carried the bag for him.

D.The conductor showed him out of the station and called a taxi.小题4:When the writer saw that the train was just moving, he felt        .

A.happy

B.angry

C.disappointed 

D.sorry小题5:Which of the following is TRUE?

A.The writer was lucky to catch the train. 

B.The driver helped the writer catch the train.

C.The writer paid the bus driver quickly. 

D.The conductor was very kind to the writer.

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