题干

在一定温度下,将气体X与气体Y各0.16mol充入10L恒容密闭容器中,发生反应:X(g)+Y(g)⇌2Z(g)△H<0,一段时间后达到平衡.反应过程中测定的数据如表:下列说法正确的是(  )

t∕min

2

4

7

9

n(Y)∕mol

0.12

0.11

0.10

0.10

A:反应前4min的平均反应速率υ(Z)=0.0125 mol•L﹣1•min﹣1

B:其他条件不变,降低温度,反应达到新平衡前υ(逆)>υ(正)

C:该温度下此反应的平衡常数K=1.44

D:其他条件不变,再充入0.2molZ,达平衡时X的体积分数增大

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C

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Hi Brad,
    It's good to hear from you again. I find that I'm not good at writing compositions. It's hard for me to prepare the form of a composition and organize sentences. ①Could you tell me how to deal with this problem? I would really appreciate if you offer me some good methods.
Best wishes,
Cindy
Hi Cindy,
    A composition is really a story and any story is told to an audience. There is a form for this and it is in three parts. First, tell them(the audience) what you are going to tell them. Then tell them, and finally tell them what you told them. Parts one and three are short and most of the information is in part two. It works like this.
    Let's say you are asked to write a 200-word composition about your visit to the Great Wall. You would begin with an opening sentence or two saying something like “The Great Wall of China is a national ②landmark that is famous around the world. I visited it last summer and I want to tell you about it.” That uses about 25 words to tell them what you are going to tell them.
    The second part would be about 150 words and would contain information about the Great Wall such as how long it is, when it was built, who built it and why, the fact that it is one of the seven wonders of the world and you would talk about how you felt and what you thought when you visited this national treasure. This is telling them.
    Finally, you would use about another 25 words to say something like “That was my first visit to the Great Wall and it was a very emotional experience to actually touch something so old and famous.③每个中国人至少参观长城一次.I plan to go back whenever I can.” Here, you are telling them what you told them in the story and wrapping it all up into a neat package. This formula(惯例)works for both compositions and speeches and I think you will find it helps to organize your thoughts. I hope it's helpful.
Best wishes,
Brad Franklin