问题 填空题

(9分)现有可逆反应A(g)+B(g)     3C(g),下图中甲、乙、丙分别表示在不同的条件下,生成物C在反应混和物中的百分含量(C%)和反应时间的关系:

(1)若甲图中两条曲线分别表示有催化剂和无催化剂时的情况,则___曲线是表示有催化剂时的情况。

(2)若乙图中的a曲线表示200℃和b曲线表示100℃时的情况,则此可逆反应的正反应是_____热反应。

(3)若丙图中两条曲线分别表示不同压强下的情况,则____曲线是表示压强较大的情况。

答案

(1)a   (2)吸   (3)b

(1)中考查催化剂对反应速率及转化率的影响,催化剂一般是加快化学反应速率,缩短到达平衡所用的时间,不能提高反应物的转化率,故选a。(2)中考查温度对反应热效应的影响,根据“先拐先平”的原则,a曲线先达到平衡,说明a曲线情况是温度高;再根据温度升高,平衡向着体系温度降低的方向移动,即该可逆反应的正反应是吸热反应。(3)中考查压强对反应速率及转化率的影响,压强增大,反应速率加快,反应首先达到平衡,即b曲线先达到平衡;再根据压强增大,C%反而降低,说明正反应是气体体积增大的反应,跟题意相一致,故选b。

选择题
阅读理解

阅读理解。

                                How Many Lies Do the Children Tell You?

     Mothers who feel their children don' t appreciate them can add another grievance to the list: half

the time, their children are lying to them.A study designed to expose the truth about lying shows that

undergraduates lie to their mothers in 46% of their conversations.Still, mums should feel better than

total strangers, who are told lies an astonishing 77 % of the time.

     Bella Depaulo and a team of psychologists from the University of Virginia, Charlottesville, asked

77 undergraduates to keep a record of all their conversations for a week, and write down whethe

r they lied at any time.DePaulo named lying broadly, as "when you intentionally try to mislead

someone", so she would catch the smallest of lies.

     The students told an average of two lies a day.They said they had been studying when they had

been out drinking.One told his parents that a textbook cost $50 rather than $20 so that they would

send him extra money.Female students constantly told their plain-looking roommates that they were

pretty."They are everyday lies," says DePaulo.

     DePaulo and her colleagues conclude that people tend to tell fewer lies to those they feel closest to.

College students lied to their best friends 28% of the time but lied to acquaintances 48% of the time.

In close relationships, people were more likely to tell "kind-hearted" lies, designed to protect feelings,

rather than self-serving lies.

     Romantic partners are somewhere between close friends and acquaintances.Students lied to

romantic partners about a third of the time. DePaulo thinks that unmarried lovers can expect less honesty

than best friends because of the insecurity that comes with romance.

     Mothers can take heart from one other finding. They may have been lied to, but at least their children

talked to them.The students were recorded telling few lies to their fathers because they had little

interaction with them.

1. According to the passage, college students felt closest to ______.

A. mothers            

B. best friends    

C. acquaintance        

D. romantic partners

2. Female students lied to their roommates to       .

A. get money from them          

B. offer them the services

C. gain more security      

D. make them happy

3. What is the purpose of this article?

A. To present a fact.              

B. To argue an idea.

C. To tell a story.            

D. To explain a theory.