问题 选择题

某温度下,在一容积不变的密闭容器中,A(g)+2B(g)⇌3C(g)达到平衡时,A.B和C的物质的量分别为3mol、2mol和4mol,若温度不变,向容器内的平衡混合物中再加入A、C各lmol,此时该平衡移动的方向为(  )

A.向左移动

B.向右移动

C.不移动

D.无法判断

答案

方法一:假设容器体积为1L,达到平衡时,A、B和C的物质的量分别为3mol、2mol和4mol,则浓度分别为3moL/L、2mol/L、4mol/L,平衡常数为k=

43
22
=
16
3

向容器内的平衡混合物中再加入A、C各lmol,此时A、B和C的浓度分别为4moL/L、2mol/L、5mol/L,

则此时QC=

53
22
=7.8125>
16
3
=5.333,

则平衡向左移动,

方法二:可用运用一边倒法,达到平衡后把C的量转化到 A、B,可以得到A、B的物质的量比值为13:14;另外添加如果是还保持这个比例,则平衡不移动,假设在另一个相同容器中加入A、C各lmol,把C的量转化到A、B,可得到A、B的物质的量比值为2:1=13:6.5,压入同一体积容器,相当于减少了B的物质的量 即减小其浓度导致平衡左移.

故选A.

阅读理解

“Who is Gogo?” Almost every pupil in Hong Kong, Japan, Taiwan and Thailand will tell you: “Gogo is from outer space and is teaching children to speak and read English.”

Gogo has visited Hong Kong, Taiwan, Japan, Thailand and Korea. Now he is in China’s mainland—“Gogo has Adventure with English” has been published by Addison Wesley Longman China Ltd (AWL).

The six level English course, full of exciting stories, educates and delights children at the same time. Gogo learns English from his friends, Tony and Jenny. The children will learn along with Gogo, enjoying all the fun he produces. Gogo has a warm place in every young learner’s heart wherever he goes.

A presentation (介绍) about Gogo was given by Beijing AWL Information Centre last November. All the pupils in Huijia School attended the presentation. A foreign teacher at Huijia later said, “The children were attracted by Gogo after only a 45-minute presentation. They remember a song taught by Gogo seven weeks later. Parents often ask me how they can help their children learn English and now there’s a programme I can direct them to.”

Clive Sawkins, Paul Price-Smiths and Gregg Schroeder worked closely at AWL to make sure that Gogo will become an easily recognized symbol (标志) of learning English wherever English is studied. “Gogo is our baby,” said Gregg. “It is very easy to get children going with Gogo.”

小题1: What is the passage mainly about?

A.Gogo visits Asian countries.

B.Gogo receives high praise.

C.Children love to learn with Gogo.

D.AWL introduces Gogo.小题2: It can be learned from the passage that Gogo is       .

A.an English teacher

B.an English boy

C.an English textbook

D.a character in an English textbook小题3: In what way is Gogo a great help to young learners?

A.He teaches them English through songs.

B.He teaches them English through adventure stories.

C.He helps them to remember English words.

D.He makes English lessons full of fun.

多项选择题