问题 选择题

在100 ℃时,将0.40 mol二氧化氮气体充入2 L密闭容器中,每隔一段时间对该容器内

的物质进行分析,得到如下数据:

时间(s)020406080
n(NO2)/mol0.40n10.26n3n4
n(N2O4)/mol0.000.05n20.080.08
 

下列说法中正确的是(  )

A.反应开始20 s内以二氧化氮表示的平均反应速率为0.001 25 mol·L-1·s-1

B.80 s时混合气体的颜色与60 s时相同,比40 s时的颜色深

C.80 s时向容器中加入0.32 mol氦气,同时将容器扩大为4 L,则平衡将不移动

D.若起始投料为0.20 mol N2O4,相同条件下达平衡,则各组分含量与原平衡体系对应相等

答案

答案:D

发生反应2NO2(g)  N2O4(g),前20 s内v(N2O4)==0.001 25 mol·L-1·

s-1,v(NO2)=0.002 5 mol·L-1·s-1,A错误。60 s、80 s时n(NO2)=0.24 mol,比40 s时的浓度小,颜色浅,B错误。容器体积增大,压强减小,平衡向逆反应方向移动,C错误。

阅读理解

先阅读短文,然后根据要求答题。

   The Dragon Boat Festival (端午节) is the day to remember a Chinese national hero, Qu Yuan, who threw

himself into the river and died over 2,000 years ago. Old story has it that people, in order to save Qu Yuan,

beat drums to drive fish away, and threw rice dumplings (zong zi) into the river to keep the fish from eating

his body. 

    For thousands of years, people have spent the festival by eating zong zi and holding dragon boat races on

the fifth day of the fifth lunar(阴历的) month, especially in the provinces where there are many

rivers and lakes. 

    The dragon boat races that many people want to save Qu's body. Those races are the most exciting

part of the festival, with very large crowds of people watching them. The special boats, more than 10 meters

long, have colorful "dragon"heads and tails (尾巴), and boat carries a team of 20 or 22 players. Every

year dragon boat races take place in southeast Asian countries and some western countries, including America,

Canada, Australia and New Zealand.

一. 根据短文内容完成下列语音题:

1. Write out the word .

2. Write out the word .

3. Write out the word .

4. In the underlined sentence find two words that can be read together (连读).

5. In the underlined sentence find a word whose last sound can have incomplete plosion(失去爆破). 

二. 根据短文内容填入一个适当的词:

1. The Dragon Boat Festival is the day for people to keep Qu Yuan in their _____.

2. The Dragon Boat Festival has a history of more than two _____ years.

3. Since the Dragon Boat Festival falls on the fifth day of the fifth lunar month, can we call it "The Double _____

Festival"?

4. Dragon boat races are mostly held in South China because there are more _____ areas there.

5. Dragon boat races are becoming more and more _____ in the world.

单项选择题